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WORM_IRCBOT.WPHB

July 22, 2014
 Analysis by: Vincent Martin Hermosura
 ALIASES:

W32/SDBot.ZPE!tr.bdr (Fortinet),Backdoor.Win32.Bifrose (Ikarus), Backdoor.Win32.Sdbot.zpe (Kaspersky), Backdoor:Win32/IRCbot.gen!S (Microsoft), W32/IRCbot.worm (NAI), Win32/Boberog.AD worm (Nod32), W32.IRCBot (Norton), Backdoor.IRCBot (Sunbelt), IRC-Worm.Generic.5236 (Bitdefender)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Propagates via flashdrives, Propagates via IRC


This worm arrives via removable drives.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system. It takes advantage of software vulnerabilities to propagate across networks.

  TECHNICAL DETAILS

File Size:

852,480 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

16 Jul 2014

Arrival Details

This worm arrives via removable drives.

Installation

This worm drops the following copies of itself into the affected system and executes them:

  • %Windows%\system\wmisynd.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

Autostart Technique

This worm registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WMISYND
ImagePath = "%Windows%\system\wmisynd.exe"

Other System Modifications

This worm adds the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WMISYND

Propagation

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

  • {removable driveletter}:\RECYCLER\S-1-6-25-2434476501-1644491937-600003330-2300\folder64.exe\folder64.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[autorun]
open=RECYCLER\S-1-6-25-2434476501-1644491937-600003330-2300\folder64.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\S-1-6-25-2434476501-1644491937-600003330-2300\folder64.exe
shell\open\default=1

It takes advantage of the following software vulnerabilities to propagate across networks:

NOTES:

This malware connects to a remote IRC server, once connected, it joins an IRC channel where it receives commands from a malicious user. The user may perform the following commands:

    Create/Kill Process and threads
  • Download/Upload files
  • Join IRC Channel
  • Propagate Self
  • Serve as HTTP/FTP server
  • Update self

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.926.02

FIRST VSAPI PATTERN DATE:

16 Jul 2014

VSAPI OPR PATTERN File:

10.927.00

VSAPI OPR PATTERN Date:

16 Jul 2014

Step 1

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 2

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 3

Delete this registry key

[ 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • WMISYND

Step 4

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.

  • Vulnerability in Server Service Could Allow Remote Code Execution (958644)

Step 5

Search and delete AUTORUN.INF files created by WORM_IRCBOT.WPHB that contain these strings

[ Learn More ]
[autorun]
open=RECYCLER\S-1-6-25-2434476501-1644491937-600003330-2300\folder64.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\S-1-6-25-2434476501-1644491937-600003330-2300\folder64.exe
shell\open\default=1

Step 6

Scan your computer with your Trend Micro product to delete files detected as WORM_IRCBOT.WPHB. 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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