WORM_PALEVO.FH
W32/Pincav.APZQ!tr (Fortinet), Trojan.Win32.Pincav (Ikarus), Trojan.Win32.Pincav.apzq (Kaspersky), Win32/AutoRun.Agent.ZM worm (NOD32)
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: Yes
In the wild: Yes
OVERVIEW
Propagates via flashdrives
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 executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
1,486,848 bytes
EXE
Yes
11 Jan 2011
Drops files, Connects to URLs/IPs
Arrival Details
This worm arrives via removable drives.
Installation
This worm drops the following copies of itself into the affected system:
- %User Profile%\Application Data\vfbu.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- K/Fz+56
It injects itself into the following processes as part of its memory residency routine:
- explorer.exe
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\Winlogon
Taskman = "%User Profile%\Application Data\vfbu.exe"
Other System Modifications
This worm adds the following registry keys:
HKEY_CURRENT_USER\Software\Licenses
HKEY_CLASSES_ROOT\CLSID\{5A8A1D95-22E9-3963-2E06-90BDD094E562}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5A8A1D95-22E9-3963-2E06-90BDD094E562}\InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5A8A1D95-22E9-3963-2E06-90BDD094E562}\ProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5A8A1D95-22E9-3963-2E06-90BDD094E562}\VersionIndependentProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
RFC1156Agent
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Licenses
{K7C0DB872A3F777C0} = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5A8A1D95-22E9-3963-2E06-90BDD094E562}\InprocServer32
ThreadingModel = "Both"
HKEY_CURRENT_USER\Software\Licenses
{IAA4A1823DF778B97} = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
RFC1156Agent\CurrentVersion\Parameters
TrapPollTimeMilliSecs = "3a98"
Propagation
This worm creates the following folders in all removable drives:
- {Removable Drive}:\U3ROM
It drops the following copy(ies) of itself in all removable drives:
- {removable drive letter}:\U3ROM\system32.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:
;garbage characters
[autorun]
open=U3ROM/system32.exe
;garbage characters
icon=U3ROM/default.ico
;garbage characters
action=Open
;garbage characters
shell\open\command=U3ROM/system32.exe
shell\explore\command=U3ROM/system32.exe
useautoplay=1
:GOTO NUL
;garbage characters
Backdoor Routine
This worm executes the following commands from a remote malicious user:
- MSN spreader
- P2P Spreader
- DDOS (TCP/UDP Flooding)
- Retrieve Stored Browser Passwords
- Update / Remove self
- Download and execute arbitrary files
- USB Spreader
- Visit a URL / Display pop-up advertisements
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}cureupdate.com
- {BLOCKED}dates2000.com
- {BLOCKED}servis.in
- {BLOCKED}windows.net
- {BLOCKED}ureserv.com
However, as of this writing, the said sites are inaccessible.
Information Theft
This worm gathers the following data:
- IP Address
- Network Setting
- Operation System
- Admin Rights
- Country
- Port Used
- Username / Hostname
NOTES:
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
9.300
10.286.05
09 Sep 2013
10.269.00
10 Sep 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
Identify and delete files detected as WORM_PALEVO.FH using either the Startup Disk or Recovery Console
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Winlogon
- Taskman = "%User Profile%\Application Data\vfbu.exe"
- Taskman = "%User Profile%\Application Data\vfbu.exe"
Step 4
Delete this registry key
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
- Licenses
- Licenses
- In HKEY_CLASSES_ROOT\CLSID
- {5A8A1D95-22E9-3963-2E06-90BDD094E562}
- {5A8A1D95-22E9-3963-2E06-90BDD094E562}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft
- RFC1156Agent
- RFC1156Agent
Step 5
Search and delete this folder
Step 6
Search and delete AUTORUN.INF files created by WORM_PALEVO.FH that contain these strings
Step 7
Scan your computer with your Trend Micro product to delete files detected as WORM_PALEVO.FH. 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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