TROJ_CUTWAIL.ON
Trojan:Win32/Dynamer!dtc(Microsoft), Trojan-Downloader.Win32.Cutwail.bw (v)(Sunbelt)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan 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
19,152 bytes
EXE
Yes
29 Jul 2013
Arrival Details
This Trojan 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 Trojan drops the following copies of itself into the affected system:
- %User Profile%\xsml9by46l.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 Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
xsml9by46l = "%User Profile%\xsml9by46l.exe"
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
xsml9by46l = "{random value}"
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{pseudorandom alpha characters}.ru
- http://{pseudorandom alpha characters}.com
- http://{pseudorandom alpha characters}.kz
- http://{pseudorandom alpha characters}.net
SOLUTION
9.300
10.188.03
31 Jul 2013
10.189.00
01 Aug 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
Restart in Safe Mode
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
- xsml9by46l = "{random value}"
- xsml9by46l = "{random value}"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- xsml9by46l = "%User Profile%\xsml9by46l.exe"
- xsml9by46l = "%User Profile%\xsml9by46l.exe"
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CUTWAIL.ON. 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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