WORM_CORSIVON.E
Worm:Win32/Corsivon.A (Microsoft); Trojan-FEFS!42D12DF3CB09 (McAfee); Trojan.Win32.Agent.xmpr (Kaspersky); Mal/Sisron-D (Sophos); Trojan.Win32.Sisron.c (v) (Sunbelt); Trojan horse Agent4.AOUW (AVG)
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
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.
TECHNICAL DETAILS
1,630,208 bytes
EXE
Yes
15 Aug 2014
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 copies of itself into the affected system:
- %System%\iexplore.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\Run
microsoftiexplore = "%System%\iexplore.exe"
NOTES:
It uses the icon of a folder to disguise itself. It then opens the folder that has the same name as the malware name and is located in the same directory as the malware path. The malware does this by tricking the user that it only opens a folder.
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Restart in Safe Mode
Step 4
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\Run
- microsoftiexplore = %System%\iexplore.exe
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_CORSIVON.E. 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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