General

  • Target

    OptiFine_1.19.4_HD_U_I4.jar

  • Size

    6.7MB

  • Sample

    241031-a5v58swral

  • MD5

    2e58bf463ec7e9964fe381a5afc17da1

  • SHA1

    40a44c00d4f06ba82e97b8eb71aab3823f4e9d93

  • SHA256

    2c010bcae341cf1003c194a4b566a0cb0c8dff2443d2f9fbd9e7a2d9abc8af6a

  • SHA512

    94d0673370168322cc6ba5ae7bc9ad5d5c4246aa10f8929239dedc25639255c807c32ea248ee751c42aed9ca61cf37ab391d7d3a9ba57bc643e091c9ef4009d1

  • SSDEEP

    98304:+4T54pxq3gbAuFu0Lw6jEKuBj036dh1KyMH9vPMDNgPjDbHA:+4TCxq3gtFuiWKufdh1jA9H7LPg

Malware Config

Extracted

Family

quasar

Attributes
  • reconnect_delay

    5000

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

10.127.0.227:4782

Mutex

cc382a3d-9ce3-4b59-ba4b-40acd01a72a5

Attributes
  • encryption_key

    955952829EF4D4C700D061DBC84790B29C3FF5DD

  • install_name

    Client.exe

  • log_directory

    Logs

  • reconnect_delay

    3000

  • startup_key

    Java update

  • subdirectory

    SubDir

Targets

    • Target

      OptiFine_1.19.4_HD_U_I4.jar

    • Size

      6.7MB

    • MD5

      2e58bf463ec7e9964fe381a5afc17da1

    • SHA1

      40a44c00d4f06ba82e97b8eb71aab3823f4e9d93

    • SHA256

      2c010bcae341cf1003c194a4b566a0cb0c8dff2443d2f9fbd9e7a2d9abc8af6a

    • SHA512

      94d0673370168322cc6ba5ae7bc9ad5d5c4246aa10f8929239dedc25639255c807c32ea248ee751c42aed9ca61cf37ab391d7d3a9ba57bc643e091c9ef4009d1

    • SSDEEP

      98304:+4T54pxq3gbAuFu0Lw6jEKuBj036dh1KyMH9vPMDNgPjDbHA:+4TCxq3gtFuiWKufdh1jA9H7LPg

    • Quasar RAT

      Quasar is an open source Remote Access Tool.

    • Quasar family

    • Quasar payload

    • Suspicious use of NtCreateProcessExOtherParentProcess

    • Downloads MZ/PE file

    • Uses Session Manager for persistence

      Creates Session Manager registry key to run executable early in system boot.

    • Checks computer location settings

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

    • Executes dropped EXE

    • Loads dropped DLL

    • Adds Run key to start application

    • Checks for any installed AV software in registry

    • 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

MITRE ATT&CK Enterprise v15

Tasks