General

  • Target

    https://obrowser.github.io/obrowser/

  • Sample

    240526-kmhsasde39

Malware Config

Targets

    • Target

      https://obrowser.github.io/obrowser/

    • Modifies WinLogon for persistence

    • UAC bypass

    • Deletes shadow copies

      Ransomware often targets backup files to inhibit system recovery.

    • Downloads MZ/PE file

    • Drops file in Drivers directory

    • Modifies Installed Components in the registry

    • Checks computer location settings

      Looks up country code configured in the registry, likely geofence.

    • Drops startup file

    • Executes dropped EXE

    • Loads dropped DLL

    • Modifies system executable filetype association

    • Reads user/profile data of web browsers

      Infostealers often target stored browser data, which can include saved credentials etc.

    • Registers COM server for autorun

    • Adds Run key to start application

    • Enumerates connected drives

      Attempts to read the root path of hard drives other than the default C: drive.

    • Legitimate hosting services abused for malware hosting/C2

    • Writes to the Master Boot Record (MBR)

      Bootkits write to the MBR to gain persistence at a level below the operating system.

    • Drops file in System32 directory

    • Sets desktop wallpaper using registry

    • Suspicious use of SetThreadContext

MITRE ATT&CK Enterprise v15

Tasks