General

  • Target

    SystemBlocker.zip

  • Size

    215KB

  • Sample

    221124-ychansed58

  • MD5

    7da4e010d4d61005804de323e2a11ec7

  • SHA1

    8892f1f0a32560982cf5093afc3904c4bf2598c7

  • SHA256

    a03c529337d92e04f07fd09612cdf5fb335b1d96bf711f8d57a1d06ded2b6505

  • SHA512

    5fd88a6086bf0835852093dc18c45347ae7b3b40f1273673e8c099d9ea49f58c07f305a60593ef20af79f072a1e547f69e2e7dc6590a7d8377dee33573f1e979

Malware Config

Targets

    • Target

      Convert_mp4_to_mkv.exe

    • Size

      290KB

    • MD5

      62878b796562c411dd59d57dc2076967

    • SHA1

      8f49669864e863ba3a081fe3bd10d88bfc01a10f

    • SHA256

      f3c1bfeb62067c797eb43f47daec11e72c0cbc85d5c26ca001caba5f2732d20a

    • SHA512

      49dd25c2c071376ccdf18ca2bc9d6c03a12226d1bd5e7cc04184d87b9e68c75cd4b4b3bd4d135ede3c821a65609ee26d97adecad9b89ccc5dfdc185d6c5b3795

    • Chaos

      Ransomware family first seen in June 2021.

    • Chaos Ransomware

    • Deletes shadow copies

      Ransomware often targets backup files to inhibit system recovery.

    • Modifies boot configuration data using bcdedit

    • Deletes backup catalog

      Uses wbadmin.exe to inhibit system recovery.

    • Disables Task Manager via registry modification

    • Downloads MZ/PE file

    • Executes dropped EXE

    • Modifies Installed Components in the registry

    • Modifies extensions of user files

      Ransomware generally changes the extension on encrypted files.

    • UPX packed file

      Detects executables packed with UPX/modified UPX open source packer.

    • Checks computer location settings

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

    • Drops startup file

    • Loads dropped DLL

    • Reads user/profile data of web browsers

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

    • Drops desktop.ini file(s)

    • Enumerates connected drives

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

    • Detected potential entity reuse from brand microsoft.

    • Drops file in System32 directory

    • Sets desktop wallpaper using registry

MITRE ATT&CK Matrix