RANSOM_MIRCOP.D

 Analysis by: Julie Anne Cabuhat

 ALIASES:

Ransom.Microcop (Malwarebytes), Ransom:Win32/Pocrimcrypt.A (Microsoft)

 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.

  TECHNICAL DETAILS

File Size:

1,077,960 bytes

File Type:

EXE

File Compression:

UPX

Memory Resident:

Yes

Initial Samples Received Date:

01 Dec 2016

Payload:

Drops files, Encrypts files, Renames files, Deletes files

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.

Other System Modifications

This Trojan changes the desktop wallpaper by modifying the following registry entries:

HKCU\Control Panel\Desktop
Wallpaper = %User Temp%\wl.jpg

It sets the system's desktop wallpaper to the following image:

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\8x8x8
  • %User Temp%\wl.jpg - Ransom note/Wallpaper
  • %User Temp%\x.exe - copy of malware

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on 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 Details

This Trojan renames encrypted files using the following names:

  • Lock.{file name}.{file extension}

NOTES:

The ransomware affects the following locations:

  • %Desktop%
  • %Application Data%
  • %AppDataLocal%
  • %User Profile%\Music
  • %User Profile%\Pictures
  • %User Profile%\Videos
  • %User Profile%\Documents
  • %System Root%\Users\Public\Documents
  • %System Root%\Users\Public\Pictures
  • %System Root%\Users\Public\Videos
  • {Root of hard disk drives}
If the location contains folders, it encrypts the folder and proceeds to delete all its contents.

It constantly sets the registry to set the wallpaper to the ransom note.

  SOLUTION

Minimum Scan Engine:

9.800

VSAPI OPR PATTERN File:

13.137.00

VSAPI OPR PATTERN Date:

05 Jan 2017

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_CURRENT_USER\Control Panel\Desktop
    • Wallpaper = "%User Temp%\wl.jpg"

Step 5

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Temp%\8x8x8
  • %User Temp%\wl.jpg
  • %User Temp%\x.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_MIRCOP.D. 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 7

Reset your Desktop properties

[ Learn More ]

Step 8

Restore encrypted files from backup.


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