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RANSOM_ADAMLOCK.A

January 06, 2017
 Analysis by: Marvelous Pelin
 ALIASES:

Ransom.AdamLocker(Malwarebytes);

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It adds certain registry entries to disable the Task Manager. This action prevents users from terminating the malware process, which can usually be done via the Task Manager.

  TECHNICAL DETAILS

File Size:

477,184 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

27 Dec 2016

Payload:

Encrypts files, Connects to URLs/IPs, Displays graphics/image

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops a copy of itself in the following folders using different file names:

  • %ProgramData%\run.exe

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CLASSES_ROOT\.adam
{default} = adam

HKEY_CLASSES_ROOT\adam\shell\
open\command
{default} = {malware path and filename} %l

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFolderOptions = 1

(Note: The default value data of the said registry entry is {user preference}.)

HKEY_CURRENT_USER\Software\Mircrosoft\
Windows\CurrentVersion\Policies\
Explorer
NoRun = 1

(Note: The default value data of the said registry entry is {user preference}.)

HKEY_CURRENT_USER\Software\Mircrosoft\
Windows\CurrentVersion\Policies\
Explorer
NoRightClick = 1

(Note: The default value data of the said registry entry is {user preference}.)

It adds the following registry entries to disable the Task Manager:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1

(Note: The default value data of the said registry entry is {user preference}.)

Propagation

This Trojan drops the following copy(ies) of itself in all removable drives:

  • run.exe

It modifies the contents of an existing AUTORUN.INF file to automatically execute its dropped copy. It does this by adding the following strings in the .INF file:

  • [autorun]
  • shellexecute=run.exe

Other Details

This Trojan renames encrypted files using the following names:

  • {original filename and extension}.adam

It does the following:

  • Encrypts files in the following directories:
    • %User Profile%\Documents
    • %User Profile%\Pictures
    • %User Profile%\Downloads
    • %User Profile%\Desktop
    • D:\
  • This ransomware requires a key in order to decrypt the encrypted files. The key is "8jg7RPUMOvLBwr6WK6tf".
  • It displays the following after successfully entering the required key:

Mobile Malware Routine

This Trojan accesses the following URL(s) to send and receive commands from a remote malicious user:

  • http://{BLOCKED}f.ly/1h2U8c

NOTES:

This lockscreen is displayed by the ransomware in order to restrict the user from doing any activities on the machine/system:

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

13.120.02

FIRST VSAPI PATTERN DATE:

27 Dec 2016

VSAPI OPR PATTERN File:

13.121.00

VSAPI OPR PATTERN Date:

28 Dec 2016

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CLASSES_ROOT\.adam
    • {default} = adam
  • In HKEY_CLASSES_ROOT\adam\shell\open\command
    • {default} = {malware path and filename} %l

Step 5

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • From: NoFolderOptions = 1
      To: NoFolderOptions = {user preference}
  • In HKEY_CURRENT_USER\Software\Mircrosoft\Windows\CurrentVersion\Policies\Explorer
    • From: NoRun = 1
      To: NoRun = {user preference}
  • In HKEY_CURRENT_USER\Software\Mircrosoft\Windows\CurrentVersion\Policies\Explorer
    • From: NoRightClick = 1
      To: NoRightClick = {user preference}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • From: DisableTaskMgr = 1
      To: DisableTaskMgr = {user preference}

Step 6

Search and delete AUTORUN.INF files created by RANSOM_ADAMLOCK.A that contain these strings

[ Learn More ]
  • [autorun]
  • shellexecute=run.exe

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_ADAMLOCK.A. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 8

Restore encrypted files from backup.


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