WORM_PALEVO.PH
Sophos : Mal/Palevo-A; Mcafee : W32/Rimecud.gen.g
Windows 2000, XP, Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Propagates via flashdrives
This worm drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
TECHNICAL DETAILS
328,192 bytes
EXE
Yes
24 Mar 2011
Drops files, Downloads files
Installation
This worm drops the following copies of itself into the affected system:
- %Application Data%\ygmdrm.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
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 = %Application Data%\ygmdrm.exe
Propagation
This worm creates the following folders in all removable drives:
- [DRIVE:]\ZIVOT
It drops the following copy(ies) of itself in all removable drives:
- [DRIVE:]\ZIVOT\ucio.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]
shellexecute=ZIVOT//ucio.exe
shell\explore\command=ZIVOT//ucio.exe
open=ZIVOT///ucio.exe
icon=ZIVOT//ucio.exe
shell\open\command=ZIVOT//ucio.exe
;{garbage codes}
Shell\open\command=ZIVOT//ucio.exe
USEAUTOPLAY=1
action=Open folder to view file using Windows Explorer
Download Routine
This worm accesses the following websites to download files:
- http://{BLOCKED}e.vn/mali.exe - detected as TROJ_AGENT.ZMWQ
It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
SOLUTION
8.900
07.922.08
24 Mar 2011
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Identify and delete files detected as WORM_PALEVO.PH using the 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 = %Application Data%\ygmdrm.exe
- Taskman = %Application Data%\ygmdrm.exe
Step 4
Search and delete these folders
Step 5
Search and delete AUTORUN.INF files created by WORM_PALEVO.PH that contain these strings
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_PALEVO.PH. 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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