WORM_PHOREX.B
PWS:Win32/Phorex.A (Microsoft), Trojan-PSW.Win32.LdPinch.guf (Kaspersky)
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: No
In the wild: Yes
OVERVIEW
Propagates via removable drives
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 disables Task Manager, Registry Editor, and Folder Options.
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
348,160 bytes
EXE
Yes
24 Dec 2013
Collects system information, Connects to URLs/IPs
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 component file(s):
- %System%\syswinv32.dll - contains logged keystrokes and title of accessed applications
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It drops the following copies of itself into the affected system:
- %System%\lkavs3d.exe
- %System%\netstsys.exe
- %System%\rdatdll5.exe
- %System%\wndscsy.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
System Servicet = "rdatdll5.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
Options3 = "rdatdll5.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Winlogo Startupc = "explorer.exe rdatdll5.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Settings2 = "rdatdll5.exe"
Other System Modifications
This worm creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFolderOptions = "1"
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- {removable drive letter}:\chuj.exe
- {removable drive letter}:\dideli_papai.scr
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]
action=Windows Picture and Fax Viewer
open=chuj.exe
icon=chuj.exe
Information Theft
This worm gathers the following data:
- computer name
- operating system information
- volume information
- processor information
- contents of %System%\syswinv32.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Stolen Information
This worm sends the gathered information via HTTP POST to the following URL:
- http://{BLOCKED}.{BLOCKED}.166.58/m.php
NOTES:
This worm connects to the following URLs to receive information:
- http://{BLOCKED}riends.org/index.html - currently inaccessible
- http://{BLOCKED}45.{BLOCKED}b.com/index.htm - currently accessible
- http://{BLOCKED}45.{BLOCKED}s.com/index.html - currently inaccessible
- http://www.{BLOCKED}s.lt/forumas/member.php?u=27575 - currently inaccessible
- http://www.{BLOCKED}ums.com/members/20086-ilovemydog1.html - currently inaccessible
The worm will then decrypt the information in memory to identify the C&C server where it will send the stolen information.
SOLUTION
9.700
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
Scan your computer with your Trend Micro product and note files detected as WORM_PHOREX.B
Step 3
Restart in Safe Mode
Step 4
Enable Registry Editor, Task Manager, and Folder options
Step 5
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
- System Servicet = "rdatdll5.exe"
- System Servicet = "rdatdll5.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
- Options3 = "rdatdll5.exe"
- Options3 = "rdatdll5.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- Winlogo Startupc = "explorer.exe rdatdll5.exe"
- Winlogo Startupc = "explorer.exe rdatdll5.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- Settings2 = "rdatdll5.exe"
- Settings2 = "rdatdll5.exe"
Step 6
Search and delete this file
- %System%\syswinv32.dll
Step 7
Search and delete AUTORUN.INF files created by WORM_PHOREX.B that contain these strings
- [autorun]
- action=Windows Picture and Fax Viewer
- open=chuj.exe
- icon=chuj.exe
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_PHOREX.B. 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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