Malware Dok

Dok is a Trojan application disguised as a .zip file that is able to collect user credentials and install a malicious proxy server to redirect a user's network traffic (i.e. Adversary-in-the-Middle).


List of techniques used :


id description
T1027.002 Obfuscated Files or Information: Software Packing
Adversaries may perform software packing or virtual machine software protection to conceal their code. Software packing is a method of compressing or encrypting an executable. Packing an executable changes the file signature in an attempt to avoid signature-based detection. Most decompression techniques decompress the executable code in memory. Virtual machine software protection translates an executable's original code into a special format that only a special virtual machine can run. A virtual machine is then called to run this code. Utilities used to perform software packing are called packers. Example packers are MPRESS and UPX. A more comprehensive list of known packers is available, but adversaries may create their own packing techniques that do not leave the same artifacts as well-known packers to evade defenses.
T1048.003 Exfiltration Over Alternative Protocol: Exfiltration Over Unencrypted Non-C2 Protocol
Adversaries may steal data by exfiltrating it over an un-encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server. Adversaries may opt to obfuscate this data, without the use of encryption, within network protocols that are natively unencrypted (such as HTTP, FTP, or DNS). This may include custom or publicly available encoding/compression algorithms (such as base64) as well as embedding data within protocol headers and fields.
T1056.002 Input Capture: GUI Input Capture
Adversaries may mimic common operating system GUI components to prompt users for credentials with a seemingly legitimate prompt. When programs are executed that need additional privileges than are present in the current user context, it is common for the operating system to prompt the user for proper credentials to authorize the elevated privileges for the task (ex: Bypass User Account Control). Adversaries may mimic this functionality to prompt users for credentials with a seemingly legitimate prompt for a number of reasons that mimic normal usage, such as a fake installer requiring additional access or a fake malware removal suite. This type of prompt can be used to collect credentials via various languages such as AppleScript and PowerShell. On Linux systems adversaries may launch dialog boxes prompting users for credentials from malicious shell scripts or the command line (i.e. Unix Shell). Adversaries may also mimic common software authentication requests, such as those from browsers or email clients. This may also be paired with user activity monitoring (i.e., Browser Information Discovery and/or Application Window Discovery) to spoof prompts when users are naturally accessing sensitive sites/data.
T1059.002 Command and Scripting Interpreter: AppleScript
Adversaries may abuse AppleScript for execution. AppleScript is a macOS scripting language designed to control applications and parts of the OS via inter-application messages called AppleEvents. These AppleEvent messages can be sent independently or easily scripted with AppleScript. These events can locate open windows, send keystrokes, and interact with almost any open application locally or remotely. Scripts can be run from the command-line via osascript /path/to/script or osascript -e "script here". Aside from the command line, scripts can be executed in numerous ways including Mail rules, Calendar.app alarms, and Automator workflows. AppleScripts can also be executed as plain text shell scripts by adding #!/usr/bin/osascript to the start of the script file. AppleScripts do not need to call osascript to execute. However, they may be executed from within mach-O binaries by using the macOS Native APIs NSAppleScript or OSAScript, both of which execute code independent of the /usr/bin/osascript command line utility. Adversaries may abuse AppleScript to execute various behaviors, such as interacting with an open SSH connection, moving to remote machines, and even presenting users with fake dialog boxes. These events cannot start applications remotely (they can start them locally), but they can interact with applications if they're already running remotely. On macOS 10.10 Yosemite and higher, AppleScript has the ability to execute Native APIs, which otherwise would require compilation and execution in a mach-O binary file format. Since this is a scripting language, it can be used to launch more common techniques as well such as a reverse shell via Python.
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.
T1222.002 File and Directory Permissions Modification: Linux and Mac File and Directory Permissions Modification
Adversaries may modify file or directory permissions/attributes to evade access control lists (ACLs) and access protected files. File and directory permissions are commonly managed by ACLs configured by the file or directory owner, or users with the appropriate permissions. File and directory ACL implementations vary by platform, but generally explicitly designate which users or groups can perform which actions (read, write, execute, etc.). Most Linux and Linux-based platforms provide a standard set of permission groups (user, group, and other) and a standard set of permissions (read, write, and execute) that are applied to each group. While nuances of each platform’s permissions implementation may vary, most of the platforms provide two primary commands used to manipulate file and directory ACLs: chown (short for change owner), and chmod (short for change mode). Adversarial may use these commands to make themselves the owner of files and directories or change the mode if current permissions allow it. They could subsequently lock others out of the file. Specific file and directory modifications may be a required step for many techniques, such as establishing Persistence via Unix Shell Configuration Modification or tainting/hijacking other instrumental binary/configuration files via Hijack Execution Flow.
T1543.001 Create or Modify System Process: Launch Agent
Adversaries may create or modify launch agents to repeatedly execute malicious payloads as part of persistence. When a user logs in, a per-user launchd process is started which loads the parameters for each launch-on-demand user agent from the property list (.plist) file found in /System/Library/LaunchAgents, /Library/LaunchAgents, and ~/Library/LaunchAgents. Property list files use the Label, ProgramArguments , and RunAtLoad keys to identify the Launch Agent's name, executable location, and execution time. Launch Agents are often installed to perform updates to programs, launch user specified programs at login, or to conduct other developer tasks. Launch Agents can also be executed using the Launchctl command. Adversaries may install a new Launch Agent that executes at login by placing a .plist file into the appropriate folders with the RunAtLoad or KeepAlive keys set to true. The Launch Agent name may be disguised by using a name from the related operating system or benign software. Launch Agents are created with user level privileges and execute with user level permissions.
T1547.015 Boot or Logon Autostart Execution: Login Items
Adversaries may add login items to execute upon user login to gain persistence or escalate privileges. Login items are applications, documents, folders, or server connections that are automatically launched when a user logs in. Login items can be added via a shared file list or Service Management Framework. Shared file list login items can be set using scripting languages such as AppleScript, whereas the Service Management Framework uses the API call SMLoginItemSetEnabled. Login items installed using the Service Management Framework leverage launchd, are not visible in the System Preferences, and can only be removed by the application that created them. Login items created using a shared file list are visible in System Preferences, can hide the application when it launches, and are executed through LaunchServices, not launchd, to open applications, documents, or URLs without using Finder. Users and applications use login items to configure their user environment to launch commonly used services or applications, such as email, chat, and music applications. Adversaries can utilize AppleScript and Native API calls to create a login item to spawn malicious executables. Prior to version 10.5 on macOS, adversaries can add login items by using AppleScript to send an Apple events to the “System Events” process, which has an AppleScript dictionary for manipulating login items. Adversaries can use a command such as tell application “System Events” to make login item at end with properties /path/to/executable. This command adds the path of the malicious executable to the login item file list located in ~/Library/Application Support/com.apple.backgroundtaskmanagementagent/backgrounditems.btm. Adversaries can also use login items to launch executables that can be used to control the victim system remotely or as a means to gain privilege escalation by prompting for user credentials.
T1548.003 Abuse Elevation Control Mechanism: Sudo and Sudo Caching
Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges. Adversaries may do this to execute commands as other users or spawn processes with higher privileges. Within Linux and MacOS systems, sudo (sometimes referred to as "superuser do") allows users to perform commands from terminals with elevated privileges and to control who can perform these commands on the system. The sudo command "allows a system administrator to delegate authority to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while providing an audit trail of the commands and their arguments." Since sudo was made for the system administrator, it has some useful configuration features such as a timestamp_timeout, which is the amount of time in minutes between instances of sudo before it will re-prompt for a password. This is because sudo has the ability to cache credentials for a period of time. Sudo creates (or touches) a file at /var/db/sudo with a timestamp of when sudo was last run to determine this timeout. Additionally, there is a tty_tickets variable that treats each new tty (terminal session) in isolation. This means that, for example, the sudo timeout of one tty will not affect another tty (you will have to type the password again). The sudoers file, /etc/sudoers, describes which users can run which commands and from which terminals. This also describes which commands users can run as other users or groups. This provides the principle of least privilege such that users are running in their lowest possible permissions for most of the time and only elevate to other users or permissions as needed, typically by prompting for a password. However, the sudoers file can also specify when to not prompt users for passwords with a line like user1 ALL=(ALL) NOPASSWD: ALL. Elevated privileges are required to edit this file though. Adversaries can also abuse poor configurations of these mechanisms to escalate privileges without needing the user's password. For example, /var/db/sudo's timestamp can be monitored to see if it falls within the timestamp_timeout range. If it does, then malware can execute sudo commands without needing to supply the user's password. Additional, if tty_tickets is disabled, adversaries can do this from any tty for that user. In the wild, malware has disabled tty_tickets to potentially make scripting easier by issuing echo 'Defaults !tty_tickets' >> /etc/sudoers. In order for this change to be reflected, the malware also issued killall Terminal. As of macOS Sierra, the sudoers file has tty_tickets enabled by default.
T1553.004 Subvert Trust Controls: Install Root Certificate
Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers. Root certificates are used in public key cryptography to identify a root certificate authority (CA). When a root certificate is installed, the system or application will trust certificates in the root's chain of trust that have been signed by the root certificate. Certificates are commonly used for establishing secure TLS/SSL communications within a web browser. When a user attempts to browse a website that presents a certificate that is not trusted an error message will be displayed to warn the user of the security risk. Depending on the security settings, the browser may not allow the user to establish a connection to the website. Installation of a root certificate on a compromised system would give an adversary a way to degrade the security of that system. Adversaries have used this technique to avoid security warnings prompting users when compromised systems connect over HTTPS to adversary controlled web servers that spoof legitimate websites in order to collect login credentials. Atypical root certificates have also been pre-installed on systems by the manufacturer or in the software supply chain and were used in conjunction with malware/adware to provide Adversary-in-the-Middle capability for intercepting information transmitted over secure TLS/SSL communications. Root certificates (and their associated chains) can also be cloned and reinstalled. Cloned certificate chains will carry many of the same metadata characteristics of the source and can be used to sign malicious code that may then bypass signature validation tools (ex: Sysinternals, antivirus, etc.) used to block execution and/or uncover artifacts of Persistence. In macOS, the Ay MaMi malware uses /usr/bin/security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain /path/to/malicious/cert to install a malicious certificate as a trusted root certificate into the system keychain.
T1557 Adversary-in-the-Middle
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as Network Sniffing, Transmitted Data Manipulation, or replay attacks (Exploitation for Credential Access). By abusing features of common networking protocols that can determine the flow of network traffic (e.g. ARP, DNS, LLMNR, etc.), adversaries may force a device to communicate through an adversary controlled system so they can collect information or perform additional actions. For example, adversaries may manipulate victim DNS settings to enable other malicious activities such as preventing/redirecting users from accessing legitimate sites and/or pushing additional malware. Adversaries may also manipulate DNS and leverage their position in order to intercept user credentials, including access tokens (Steal Application Access Token) and session cookies (Steal Web Session Cookie). Downgrade Attacks can also be used to establish an AiTM position, such as by negotiating a less secure, deprecated, or weaker version of communication protocol (SSL/TLS) or encryption algorithm. Adversaries may also leverage the AiTM position to attempt to monitor and/or modify traffic, such as in Transmitted Data Manipulation. Adversaries can setup a position similar to AiTM to prevent traffic from flowing to the appropriate destination, potentially to Impair Defenses and/or in support of a Network Denial of Service.

List of groups using the malware :


id description

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