WORM_PALEVO.SMAH
Worm.Win32.Palevo.smgl (v) (GFI-Sunbelt); Trojan.Win32.Rimecud (Ikarus); W32/Dropper.SMAH!tr (Fortinet); W32/Rimecud.R.gen!Eldorado (Authentium)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Propagates via removable drives
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 connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats. As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Varies
EXE
Yes
25 Feb 2011
Downloads files
Arrival Details
This worm arrives via removable drives.
Installation
This worm drops the following copies of itself into the affected system:
- %User Profile%\fswagz.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.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = "%User Profile%\fswagz.exe"
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- {drive letter}:\{random folder}\{random file name}.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]
USEAUTOPLAY=1
shellexecute={random folder}/{random file name}.exe
Shell\{random string 1}\{random string 2}
Shell\\Explore\\command={random folder}/{random file name}.exe
Shell\Open\command={random folder}/{random file name}.exe
icon={random folder}/{random file name}.exe
open={random folder}/{random file name}.exe
action=Open folder to view files using Windows Explorer
Download Routine
This worm connects to the following malicious URLs:
- http://{BLOCKED}.{BLOCKED}.155.136/big/brother{random number}.exe
As of this writing, the said sites are inaccessible.
SOLUTION
8.900
7.886.12
08 Mar 2011
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.SMAH 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 NT\CurrentVersion\Winlogon
- Taskman = "%User Profile%\fswagz.exe"
Step 4
Search and delete AUTORUN.INF files created by WORM_PALEVO.SMAH that contain these strings
[AutoRun]
USEAUTOPLAY=1
shellexecute={random folder}/{random file name}.exe
Shell\{random string 1}\{random string 2}
Shell\\Explore\\command={random folder}/{random file name}.exe
Shell\Open\command={random folder}/{random file name}.exe
icon={random folder}/{random file name}.exe
open={random folder}/{random file name}.exe
action=Open folder to view files using Windows Explorer
Step 5
Scan your computer with your Trend Micro product to delete files detected as WORM_PALEVO.SMAH. 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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