RANSOM_RUNELOCKER.A

 Analysis by: Ryan Paolo Maglaque

 ALIASES:

Ransom.YeeScrLocker(Norton);MSIL/LockScreen.RC!tr(Fortinet);Ransom.YeeScrLocker(Symantec)

 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:

Dropped by other malware, Downloaded from the Internet


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:

2,870,784 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

25 Nov 2016

Payload:

Displays message/message boxes, Locks screen, 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.

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
PremierePro = {Malware File Path}

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

  • taskmgr.exe

Other Details

This Trojan does the following:

  • It locks the screen and display the following ransom note:

  • It deletes files in Desktop and subdirectories with the following file extensions:
    • bat
    • bmp
    • doc
    • docm
    • docx
    • gif
    • html
    • jpeg
    • jpg
    • mp3
    • mp4
    • pdf
    • png
    • ppt
    • pptm
    • pptx
    • psd
    • rar
    • rtf
    • txt
    • vbs
    • wav
    • xls
    • xlsm
    • xlsx
    • zip

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

12.920.03

FIRST VSAPI PATTERN DATE:

25 Nov 2016

VSAPI OPR PATTERN File:

12.921.00

VSAPI OPR PATTERN Date:

26 Nov 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • PremierePro = {Malware File Path}

Step 5

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


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