SombRAT

The content repeatedly describes malware and threat actors using obfuscated code, encrypted strings, Base64/XOR/RC4/AES encoding, VMProtect/ConfuserEx/SmartAssembly, stack strings, control-flow flattening, opaque predicates, and hidden payloads to evade analysis and detection.

The content repeatedly describes threat actors and malware deleting files, tools, scripts, logs, droppers, staged data, and artifacts from compromised systems to cover tracks, remove evidence, or self-delete.

The content repeatedly describes malware and threat actors decoding, decrypting, deobfuscating, or unpacking payloads, strings, configuration data, commands, and C2 responses prior to execution or use.

"actors used the following command ... to obtain information about services: net start"; "APT1 used the commands net start and tasklist to get a listing of the services on the system"; "OilRig has used sc query on a victim to gather information about services"; "Indrik Spider has used the win32_service WMI class to retrieve a list of services"

The content repeatedly describes malware and threat actors collecting usernames, identifying logged-in users, running whoami/query user/quser, checking whether the current user is an administrator, enumerating user sessions, and gathering account details from compromised hosts.

The content repeatedly describes malware and threat actors obtaining lists of running processes, using utilities such as tasklist, ps, WMI, Get-Process, CreateToolhelp32Snapshot, EnumProcesses, and similar APIs/commands to enumerate active processes on victim systems.

The content repeatedly describes malware and threat actors collecting host details such as OS version, hostname, architecture, CPU, memory, BIOS, domain, language, and other configuration data; e.g., "APT41 uses multiple built-in commands such as systeminfo and net config Workstation to enumerate victim system basic configuration information."

The content repeatedly describes malware and threat actors listing files and directories, enumerating drives, searching for files by extension/name/path, retrieving file metadata, and browsing file systems (for example: "APT28 has used Forfiles to locate PDF, Excel, and Word documents during collection" and "cmd can be used to find files and directories with native functionality such as dir commands").

Multiple malware and threat groups are described as collecting/deriving local system time, date, timestamp, tick count, or time zone (e.g., "used time /t and net time \ip/hostname for system time discovery"; "collects the timestamp from the victim’s machine"; "can collect the time zone information from the system").

The content repeatedly describes threat actors and malware collecting, stealing, identifying, copying, or staging files, documents, credentials, logs, databases, and other information from compromised hosts or local systems.

The content repeatedly describes adversaries and malware storing collected data, command output, credentials, archives, or files in local temporary folders, working directories, hidden directories, registry locations, recycle bins, or specific files prior to exfiltration.

"Aria-body has the ability to use a reverse SOCKS proxy module." / "BADHATCH can use SOCKS4 and SOCKS5 proxies..." / "Neo-reGeorg... establish a SOCKS5 proxy" / "Remcos uses the infected hosts as SOCKS5 proxies"

"APT41 used a tool called CLASSFON to covertly proxy network communications." / "BADCALL functions as a proxy server between the victim and C2 server." / "Sandworm Team's BCS-server tool can create an internal proxy server to redirect traffic..."

Aria-body has the ability to use a reverse SOCKS proxy module... BADHATCH can use SOCKS4 and SOCKS5 proxies... GoBear implements SOCKS5 proxy functionality... Neo-reGeorg has the ability to establish a SOCKS5 proxy... Remcos uses the infected hosts as SOCKS5 proxies...

"Anchor has used ICMP in C2 communications." / "COATHANGER uses ICMP for transmitting configuration information..." / "PHOREAL communicates via ICMP for C2." / "Regin ... can use ICMP to communicate between infected computers." / "Cobalt Strike can be configured to use TCP, ICMP, and UDP for C2 communications."

APT41 has used DGAs to change their C2 servers monthly. Aria-body has the ability to use a DGA for C2 communications. Astaroth has used a DGA in C2 communications. Bazar can implement DGA using the current date as a seed variable.

The content repeatedly describes malware and threat actors using SSL, TLS, HTTPS, RSA, AES, Blowfish, RC4, ECIES, Diffie-Hellman, OpenSSL, WolfSSL, and mutual TLS to protect command and control traffic.

Multiple malware families and intrusion sets are described as encrypting C2 traffic using SSL/TLS/HTTPS (e.g., "used HTTPS for command and control", "encrypts C2 communications with TLS", "uses SSL for encrypting C2 communications", "TLS-encrypted WebSocket Protocol (WSS) for C2").

ADVSTORESHELL exfiltrates data over the same channel used for C2... Agrius exfiltrated staged data using tools such as Putty and WinSCP, communicating with command and control servers... numerous malware and groups sent victim data, files, credentials, or host information over existing C2 channels.