AvosLocker

Across the content, malware repeatedly 'adds Registry Run keys', 'creates Registry entries', 'modifies the Windows Registry', or 'overwrites registry keys' to maintain persistence.

Examples include AppleSeed creating 'HKCU\Software\Microsoft/Windows\CurrentVersion\RunOnce', AvosLocker executed via the RunOnce Registry key, NanoCore creating a RunOnce key, and Raspberry Robin setting a RunOnce key. | The content repeatedly describes malware and threat actors establishing persistence by adding values under HKCU/HKLM\Software\Microsoft\Windows\CurrentVersion\Run or RunOnce, and by placing executables, scripts, or .lnk files in the Startup folder.

Additionally, adversaries may exploit legitimate drivers from anti-virus software to gain access to kernel space (i.e. Exploitation for Privilege Escalation), which may lead to bypassing anti-tampering features.

Examples include AppleSeed creating 'HKCU\Software\Microsoft/Windows\CurrentVersion\RunOnce', AvosLocker executed via the RunOnce Registry key, NanoCore creating a RunOnce key, and Raspberry Robin setting a RunOnce key. | The content repeatedly describes malware and threat actors establishing persistence by adding values under HKCU/HKLM\Software\Microsoft\Windows\CurrentVersion\Run or RunOnce, and by placing executables, scripts, or .lnk files in the Startup folder.

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.

During the 2016 Ukraine Electric Power Attack, Sandworm Team masqueraded executables as .txt files.

Kapeka masquerades as a Microsoft Word Add-In file, with the extension .wll, but is a malicious DLL file.

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.

Agent Tesla has used ProcessWindowStyle.Hidden to hide windows. APT19 used -W Hidden to conceal PowerShell windows by setting the WindowStyle parameter to hidden. APT28 has used the WindowStyle parameter to conceal PowerShell windows.

Across the content, malware repeatedly 'adds Registry Run keys', 'creates Registry entries', 'modifies the Windows Registry', or 'overwrites registry keys' to maintain persistence.

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 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").

“Sandworm Team pushed additional malicious tools onto an infected system…”; repeated throughout: “can download additional payloads/files/modules from C2” and “upload/download files to/from victim’s machine.”

Since early 2023, AvNeutralizer has been used in numerous intrusions, including with the subsequent deployment of well-known ransomware strains such as AvosLocker, MedusaLocker, BlackCat, Trigona, and LockBit.

"AcidPour includes functionality to reboot the victim system following wiping actions..."; "AcidRain reboots the target system once the various wiping processes are complete"; "Apostle reboots the victim machine following wiping"; "APT37 ... issue the command shutdown /r /t 1 to reboot a system after wiping its MBR"; "APT38 ... BOOTWRECK ... initiate a system reboot after wiping the victim's MBR"; "Black Basta ... used ShellExecuteA to shut down and restart"; "DarkGate ... used the shutdown command"; "HermeticWiper can initiate a system shutdown"; "NotPetya will reboot the system one hour after infection"; "Shamoon will reboot the infected system once the wiping functionality has been completed"; "WhisperGate can shutdown ... through ... ExitWindowsEx"

Adversaries may modify and/or disable security tools to avoid possible detection of their malware/tools and activities.

This may take many forms, such as killing security software processes or services, modifying / deleting Registry keys or configuration files so that tools do not operate properly, or other methods to interfere with security tools scanning or reporting information.