WORM_WISBIPUF.G

May 31, 2018
 Analysis by: John Donnie Celestre
 ALIASES:

Worm:MSIL/Wisbipuf (MICROSOFT), HEUR:Trojan.Win32.Generic (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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.

  TECHNICAL DETAILS

File Size:

80,896 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

28 May 2018

Payload:

Terminates processes, Modifies files

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.

Autostart Technique

This Worm adds the following registry entries 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:

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

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

Propagation

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

  • Recycle.Bin
  • System Volume

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"
    • "ألعا"

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 existence of the following files 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

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.274.03

FIRST VSAPI PATTERN DATE:

25 May 2018

VSAPI OPR PATTERN File:

14.275.00

VSAPI OPR PATTERN Date:

26 May 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 = {user preference}

Step 6

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.
  • {malware path}\info.txt
  • {malware path}\wbs.txt
  • {malware path}\wbs-start.txt
  • {malware path}\lastup.txt
  • {malware path}\data\backup.txt

Step 7

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