Worm.Win32.WRAMPLYR.A

 Analysis by: Patrick Noel Collado

 ALIASES:

Win32/Agent.OHO worm (Nod32), Worm.Win32.Agent (Ikarus)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

113,664 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

22 Dec 2021

Arrival Details

This Worm 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 Worm drops the following files:

  • {Removable Drive}\$Recycle.bin\{360322e1-13ee-11e5-824f-dc9c5213ca21}\{Computer Name}.log
    • contains the ff gathered data:
      • Current Time
      • Computer name
      • Drive's USB Driver name
      • Direction of infection
  • {Removable Drive}\$Recycle.bin.lnk

It adds the following processes:

  • If OS is Windows NT or later:
    • "schtasks /create /sc MINUTE /mo 20 /tn ""GoogleUpdateTaskMachineUAS"" /tr ""regsvr32 /s \""%AppDataLocal%\Microsoft\Media Player\{Malware Name}\"" /i:\""-s\"" "" /F"
    • "schtasks /run /tn ""GoogleUpdateTaskMachineUAS"""
  • "cmd.exe /c ping 127.0.0.1&del ""{Malware Path}\$Recycle.bin\{Malware Name}"""

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Autostart Technique

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

If OS Version is earlier than Windows NT:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
wrapper.dll = regsvr32 /s "%AppDataLocal%\Microsoft\Media Player\wrapper.dll" /i:"-s"

Propagation

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

  • {Removable Drive}\$Recycle.bin\wrapper.dll

Adware Routine

This Worm deletes itself after execution.

Other Details

This Worm does the following:

  • It continues with routine if inside its following installation folder:
    • %AppDataLocal%\Microsoft\Media Player
    • {Removable Drive}\$Recycle.bin
    • {Malware path}\$Recycle.bin
  • if "-s" parameter is NOT used it does the following:
    • Creates the following folders:
      • %AppDataLocal%\Microsoft\Media Player\{360322e1-13ee-11e5-824f-dc9c5213ca21}
      • %AppDataLocal%\Microsoft\Media Player\{5C29F891-91DD-4744-99CE-5D50E733BEA6}
    • Run BAT files found in %AppDataLocal%\Microsoft\Media Player\{5C29F891-91DD-4744-99CE-5D50E733BEA6}\
    • Searches for text files found in %AppDataLocal%\Microsoft\Media Player\{360322e1-13ee-11e5-824f-dc9c5213ca21}\ and does the following:
      • Encrypts found text files
      • Renames .txt files found to {original filepath and name}.{Computer Name}.{Current DateTime}
      • Looks for the following folders in removable drives where it transfers encrypted text files:
        • {Removable Drive}\$Recycle.bin\{360322e1-13ee-11e5-824f-dc9c5213ca21}

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It accepts the following parameters:

  • -s -Does the following:
    • Transfers the following files from installation folder:
      • %AppDataLocal%\Microsoft\Media Player\{360322e1-13ee-11e5-824f-dc9c5213ca21}
      • %AppDataLocal%\Microsoft\Media Player\{5C29F891-91DD-4744-99CE-5D50E733BEA6}
      • %AppDataLocal%\Microsoft\Media Player\wrapper.dll <- self
      • %AppDataLocal%\Microsoft\Media Player\config.ini
    • To:
      • {Removable Drive}\$Recycle.bin\{360322e1-13ee-11e5-824f-dc9c5213ca21}
      • {removable drive}\$Recycle.bin\{5C29F891-91DD-4744-99CE-5D50E733BEA6}
      • {removable drive}\$Recycle.bin\wrapper.dll <- self
      • {removable drive}\$Recycle.bin\config.ini

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

17.284.04

FIRST VSAPI PATTERN DATE:

30 Dec 2021

VSAPI OPR PATTERN File:

17.285.00

VSAPI OPR PATTERN Date:

31 Dec 2021

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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

Identify and terminate files detected as Worm.Win32.WRAMPLYR.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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 
    • wrapper.dll = regsvr32 /s "%AppDataLocal%\Microsoft\Media Player\wrapper.dll" /i:"-s"

Step 5

Search and delete these files

[ 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.
  • {Removable Drive}\$Recycle.bin\{360322e1-13ee-11e5-824f-dc9c5213ca21}\{Computer Name}.log
  • {Removable Drive}\$Recycle.bin.lnk
  • {removable drive}\$Recycle.bin\wrapper.dll <- self
  • {removable drive}\$Recycle.bin\config.ini
  • %AppDataLocal%\Microsoft\Media Player\config.ini
  • %AppDataLocal%\Microsoft\Media Player\wrapper.dll <- self

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • {Removable Drive}\$Recycle.bin
  • {Malware path}\$Recycle.bin
  • %AppDataLocal%\Microsoft\Media Player\{360322e1-13ee-11e5-824f-dc9c5213ca21}
  • %AppDataLocal%\Microsoft\Media Player\{5C29F891-91DD-4744-99CE-5D50E733BEA6}

Step 7

Scan your computer with your Trend Micro product to delete files detected as Worm.Win32.WRAMPLYR.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 the following Trend Micro Support pages for more information:


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