Mosquito

2020-03-12 ⋅ ESET Research ⋅ Tracking Turla: New backdoor delivered via Armenian watering holes ...

The content repeatedly describes threat actors and malware using WMI/WMIC/wmiexec for remote execution, lateral movement, discovery, persistence, and administrative actions; e.g., 'APT41 used WMI in several ways, including for execution of commands via WMIEXEC as well as for persistence via PowerSploit' and 'Scattered Spider used Windows Management Instrumentation (WMI) to move laterally via Impacket.'

The content repeatedly describes threat actors and malware using PowerShell to execute payloads, run commands, download additional malware, perform lateral movement, evade defenses, and execute scripts in memory. | Examples include: 'APT28 downloads and executes PowerShell scripts and performs PowerShell commands'; 'APT3 has used PowerShell on victim systems to download and run payloads after exploitation'; 'TA505 has used PowerShell to download and execute malware and reconnaissance scripts.'

The content repeatedly describes threat actors and malware using cmd.exe, the Windows command shell, to execute commands, launch payloads, run batch files, and automate actions on compromised hosts.

The content is a MITRE ATT&CK-style listing of many malware families and threat groups using Windows/native OS APIs for execution, injection, discovery, anti-debugging, and other actions, ending with 'NtCreateProcess' and 'fork()'.

ADVSTORESHELL is capable of setting and deleting Registry values. Agent Tesla can achieve persistence by modifying Registry key entries. APT41 used a malware variant called GOODLUCK to modify the registry in order to steal credentials.

Today I’ll write about the result of own research into another persistence trick: COM hijacking... COM has been employed in red teaming circumstances for persistence, lateral movement, and defense evasion... An attacker can employ a not-so-common but widely used technique to ensure silent persistence in a system

ADVSTORESHELL achieves persistence by adding itself to the HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run Registry key... APT28 has deployed malware that has copied itself to the startup directory for persistence... FIN7 malware has created Registry Run and RunOnce keys to establish persistence, and has also added items to the Startup folder.

Today I’ll write about the result of own research into another persistence trick: COM hijacking... COM has been employed in red teaming circumstances for persistence, lateral movement, and defense evasion... An attacker can employ a not-so-common but widely used technique to ensure silent persistence in a system

ADVSTORESHELL achieves persistence by adding itself to the HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run Registry key... APT28 has deployed malware that has copied itself to the startup directory for persistence... FIN7 malware has created Registry Run and RunOnce keys to establish persistence, and has also added items to the Startup folder.

The content repeatedly describes payloads, strings, configuration files, scripts, URLs, and binaries being obfuscated or encoded using Base64, XOR, RC4, AES, RSA, hex encoding, custom algorithms, and other methods across many malware families and threat actors.

Examples include 'Mosquito’s installer is obfuscated with a custom crypter,' 'PyDCrypt has been compiled and encrypted with PyInstaller, specifically using the --key flag,' and 'Threat Group-3390 malware is also obfuscated using Metasploit’s shikata_ga_nai encoder.'

The content repeatedly describes malware and threat actors deleting files, directories, droppers, logs, scripts, temporary files, exfiltrated archives, and uninstalling themselves to cover tracks or reduce forensic artifacts.

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.

ADVSTORESHELL is capable of setting and deleting Registry values. Agent Tesla can achieve persistence by modifying Registry key entries. APT41 used a malware variant called GOODLUCK to modify the registry in order to steal credentials.

AdFind can extract subnet information from Active Directory; actors used ipconfig /all, netsh.exe, ifconfig, arp, route, nbtstat, and related APIs/commands to gather IP, MAC, DNS, DHCP, gateway, proxy, routing, ARP, and adapter information.

The content repeatedly describes malware and threat actors collecting the username, identifying the current user, enumerating logged-on users, or running commands such as whoami, query user, and quser to determine user context on compromised systems.

Tasklist can be used to discover processes running on a system. Numerous malware families and threat groups are described as listing running processes, collecting PIDs, checking for specific process names, or enumerating loaded modules.

Examples include 'Action RAT can use WMI to gather AV products installed on an infected host,' 'FlawedAmmyy leverages WMI to enumerate anti-virus on the victim,' and 'TA2541 has used WMI to query targeted systems for security products.'

Adversaries may attempt to get a listing of security software, configurations, defensive tools, and sensors that are installed on a system or in a cloud environment.

Many entries describe XOR, XOR/ADD, bitwise NOT and XOR, ROR plus XOR, hexadecimal encoding after encryption, and custom encoding/obfuscation of HTTP traffic or beacons.

The content repeatedly describes malware and threat actors that can "download files from C2," "download additional payloads," "upload and download files," "retrieve payloads from the C2 server," and "copy files to remote machines."

The content is a catalog of malware and threat groups that encrypt command-and-control communications using algorithms such as DES, AES, RC4, XOR, Blowfish, RSA, Camellia, RC2, RC6, and custom ciphers.