General

  • Target

    https://pixeldrain.com/u/xLBcXGAD

  • Sample

    240212-yzjr1sbe4s

Malware Config

Extracted

Family

darkcomet

Botnet

Guest16

C2

5.39.43.50:1609

5.39.43.50:1610

Mutex

DC_MUTEX-NJU5JXL

Attributes
  • InstallPath

    MSDCSC\msdcsc.exe

  • gencode

    CyfxMZvzryrY

  • install

    true

  • offline_keylogger

    true

  • persistence

    false

  • reg_key

    MicroUpdate

Targets

    • Target

      https://pixeldrain.com/u/xLBcXGAD

    • Darkcomet

      DarkComet is a remote access trojan (RAT) developed by Jean-Pierre Lesueur.

    • Modifies WinLogon for persistence

    • Modifies firewall policy service

    • Modifies security service

    • Windows security bypass

    • Contacts a large (2609) amount of remote hosts

      This may indicate a network scan to discover remotely running services.

    • Disables RegEdit via registry modification

    • Disables Task Manager via registry modification

    • Downloads MZ/PE file

    • Drops file in Drivers directory

    • Modifies Installed Components in the registry

    • Sets service image path in registry

    • Checks BIOS information in registry

      BIOS information is often read in order to detect sandboxing environments.

    • Checks computer location settings

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

    • 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

    • Unexpected DNS network traffic destination

      Network traffic to other servers than the configured DNS servers was detected on the DNS port.

    • Windows security modification

    • Adds Run key to start application

    • Checks for any installed AV software in registry

    • Checks installed software on the system

      Looks up Uninstall key entries in the registry to enumerate software on the system.

    • Checks whether UAC is enabled

    • Creates a large amount of network flows

      This may indicate a network scan to discover remotely running services.

    • Enumerates connected drives

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

    • Installs/modifies Browser Helper Object

      BHOs are DLL modules which act as plugins for Internet Explorer.

    • Maps connected drives based on registry

      Disk information is often read in order to detect sandboxing environments.

    • Writes to the Master Boot Record (MBR)

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

    • Checks system information in the registry

      System information is often read in order to detect sandboxing environments.

    • Drops file in System32 directory

    • Suspicious use of NtSetInformationThreadHideFromDebugger

MITRE ATT&CK Matrix ATT&CK v13

Persistence

Boot or Logon Autostart Execution

5
T1547

Registry Run Keys / Startup Folder

4
T1547.001

Winlogon Helper DLL

1
T1547.004

Create or Modify System Process

2
T1543

Windows Service

2
T1543.003

Event Triggered Execution

1
T1546

Change Default File Association

1
T1546.001

Browser Extensions

1
T1176

Pre-OS Boot

1
T1542

Bootkit

1
T1542.003

Privilege Escalation

Boot or Logon Autostart Execution

5
T1547

Registry Run Keys / Startup Folder

4
T1547.001

Winlogon Helper DLL

1
T1547.004

Create or Modify System Process

2
T1543

Windows Service

2
T1543.003

Event Triggered Execution

1
T1546

Change Default File Association

1
T1546.001

Defense Evasion

Modify Registry

12
T1112

Impair Defenses

2
T1562

Disable or Modify Tools

2
T1562.001

Pre-OS Boot

1
T1542

Bootkit

1
T1542.003

Subvert Trust Controls

1
T1553

Install Root Certificate

1
T1553.004

Credential Access

Unsecured Credentials

1
T1552

Credentials In Files

1
T1552.001

Discovery

Network Service Discovery

2
T1046

Query Registry

9
T1012

System Information Discovery

10
T1082

Software Discovery

1
T1518

Security Software Discovery

1
T1518.001

Peripheral Device Discovery

2
T1120

Collection

Data from Local System

1
T1005

Tasks