WORM_IRCBOT.WPHN
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
212,992 bytes
EXE
Yes
10 Dec 2013
Downloads files, monitors visited websites
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 copies of itself into the affected system:
- {Removable Drive}:\winlog.exe
- %Application Data%\Microsoft\winlog.exe
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
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
winlog.exe = "%Application Data%\Microsoft\winlog.exe"
Propagation
This worm 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={malware path}
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command={malware path}
shell\open\default=1
Dropping Routine
This worm drops the following files:
- {Removable Drive}:\autorun.inf
Information Theft
This worm gathers the following data:
- Affected machine's visited websites in Firefox.
Other Details
This worm connects to the following URL(s) to get the affected system's IP address:
- p03.{BLOCKED}p.info
It does the following:
- Download and Execute Arbitrary Files
- UDP Flooding
- Update or Uninstall components
- Update self
SOLUTION
9.700
10.464.04
10 Dec 2013
10.465.00
11 Dec 2013
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
Restart in Safe Mode
Step 3
Delete this registry value
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
- winlog.exe = "%Application Data%\Microsoft\winlog.exe"
- winlog.exe = "%Application Data%\Microsoft\winlog.exe"
Step 4
Search and delete this file
- {Removable Drive}:\autorun.inf
Step 5
Search and delete AUTORUN.INF files created by WORM_IRCBOT.WPHN that contain these strings
For Windows Vista, Windows 7, Windows Server 2003, Windows 8, Windows 8.1, and Windows Server 2012:
- Open a Windows Explorer window.
- For Windows Vista, 7, and Server 2008 users, click Start>Computer.
- For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
- In the Search Computer/This PC input box, type:
AUTORUN.INF - Select the file, then open using Notepad.
- Check if the following lines are present in the file:
DATA_GENERIC - If the lines are present, delete the file.
- Repeat steps 3 to 5 for the remaining AUTORUN.INF files in other remaining removable drives.
- Close Search Results.
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_IRCBOT.WPHN. 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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