WORM_MSPOSER.ZF
Worm:MSIL/Necast.G (Microsoft), Infostealer (Symantec), W32/Worm-FEU (McAfee), Mal/MSIL-EY (Sophos), Worm.Generic.363194 (FSecure), Trojan.Win32.Generic!BT (Sunbelt), Worm/Necast.G.4 (Antivir), MSIL/Agent.AY (Fortinet), Worm.Win32.Msil (Ikarus), MSIL/Agent.AY worm (Eset)
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
Propagates via removable drives, Dropped by other malware, Downloaded from the Internet
This worm arrives by connecting affected removable drives to a system. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It retrieves specific information from the affected system.
TECHNICAL DETAILS
28,160 bytes
EXE
Yes
02 Jan 2014
Steals information
Arrival Details
This worm arrives by connecting affected removable drives to a system.
It 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 and executes them:
- %Windows%\system\svchost..exe (For Windows XP and prior)
- %User Profile%\Documents\suchost..exe (For Windows Vista and later)
(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %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 drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:
- %User Startup%\svchost..exe
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- movies.exe
Backdoor Routine
This worm opens the following ports:
- 587
Information Theft
This worm retrieves the following information from the affected system:
- Filenames of all .JPG files found in local drives
Stolen Information
The stolen information is saved in the following file:
- %System Root%\Users\Public\Documents\wsystem.vx (For Windows Vista and later)
- %Windows%\system\wsystem.vx (For Windows XP and prior)
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.)
It sends the data it gathers to the following email addresses via SMTP:
- {BLOCKED}iler511@gmail.com
Drop Points
This worm uses its own SMTP engine to send the stolen data using the following domain server:
- smtp.gmail.com
NOTES:
The email it sends contains the following informtation:
Subject = {Username}
Attachment = wsystem.vx
Body = mac address : {mac_address};-- file path : {file path of wsystem.vx}
Email Password = 19121990xman
SOLUTION
9.700
10.516.02
02 Jan 2014
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 terminate files detected as WORM_MSPOSER.ZF
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 3
Search and delete this file
Step 4
Scan your computer with your Trend Micro product to delete files detected as WORM_MSPOSER.ZF. 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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