Analysis by: Wilbert Vidal
ALIASES:

Worm:MSIL/Wisbipuf (Microsoft); MSIL/Agent.JD!tr (Fortinet)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • 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 may be dropped by other malware.

It modifies certain registry entries to hide file extensions.

  TECHNICAL DETAILS

File Size: 84,480 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 06 Jun 2018

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.

It may be dropped by other malware.

Autostart Technique

This Worm modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{malware name} = {malware name}.exe

Other System Modifications

This Worm modifies the following registry entries to hide file extensions:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = 1

Propagation

This Worm creates the following folder in all physical and removable drives:

  • Recycle.Bin

It drops the following copy of itself in all physical and removable drives:

  • {drive letter}:\
    where file names can be any of the following:
    • prog
    • برامج
    • movie
    • film
    • aflam
    • افلام
    • أفلام
    • اغاني
    • أغاني
    • شعبي
    • song
    • music
    • game
    • العاب
    • ألعاب

Process Termination

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

  • Google Update.exe
  • PureNet.exe

It terminates processes or services that contain any of the following strings if found running in the affected system's memory:

  • regedit
  • msconfig
  • clean
  • regist
  • unlocker
  • diskdefrag
  • autoruns

Other Details

This Worm connects to the following URL(s) to check for an Internet connection:

  • http://www.google.com

It requires the following additional components to properly run:

  • {malware path}\info.txt
  • {malware path}\wbs.txt
  • {malware path}\wbs-start.txt
  • {malware path}\lastup.txt
  • {malware path}\data\backup.txt
  • {malware path}\newupdate.txt
  • {malware path}\setting\guide.txt
  • {malware path}\update.txt

It does the following:

  • The malware tricks the user by copying itself and renaming to legit filenames changing the file icon to folder icon.
  • This worm avoids the following folder:
    • Program Files
    • ProgramData
    • Windows
    • System Volume
    • Users
    • ....

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.300.03
FIRST VSAPI PATTERN DATE: 07 Jun 2018
VSAPI OPR PATTERN File: 14.301.00
VSAPI OPR PATTERN Date: 08 Jun 2018

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
    • {malware name} = {malware name}.exe

Step 5

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: HideFileExt = "1"
      To: HideFileExt = 0

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.
  • {Drive Letter}:\Recycle.Bin

Step 7

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