TROJ_VUNDO.XPBL
TrojanDropper:Win32/Vundo.AB (Microsoft); Trojan.Vundo (Symantec); RDN/Vundo!du (McAfee); Trojan.Vundo (Malwarebytes); W32/Vundo.FI (F-Prot); TR/Vundo.Gen (Avira)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
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. It may be downloaded from remote sites by other malware.
It connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible. It deletes the initially executed copy of itself.
TECHNICAL DETAILS
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.
It may be downloaded from remote site(s) by the following malware:
- JAVA_ZUPNIC.A via ZUPONCIC Exploit Kit
Installation
This Trojan adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\{random}
Autostart Technique
This Trojan creates the following registry entries to enable automatic execution of dropped component at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
{random} = "{path}\{filename}.exe"
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random} = "{path}\{filename}.exe"
Other System Modifications
This Trojan modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\{random 1}
{random 2} = "{random values}"
HKEY_CURRENT_USER\SOFTWARE\{random 1}
{random 2} = "{random values}"
Dropping Routine
This Trojan drops the following files:
- %User Temp%\~unins{random}.bat ← delete malware's initially executed copy and itself
- {path}\{filename}.exe
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
Other Details
This Trojan connects to the following website to send and receive information:
- http://{BLOCKED}.{BLOCKED}.88.220/signin
However, as of this writing, the said sites are inaccessible.
It deletes the initially executed copy of itself
NOTES:
It installs an adware using the following name:
- {path}\{filename}.exe
- where {path} are any of the following:
- %Program Files%
- %Application Data%
- %System%
SOLUTION
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
Remove the malware/grayware file that dropped/downloaded TROJ_VUNDO.XPBL. (Note: Please skip this step if the threat(s) listed below have already been removed.)
- JAVA_ZUPNIC.A
Step 4
Restart in Safe Mode
Step 5
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\policies\Explorer\Run
- {random} = "{path}\{filename}.exe"
- {random} = "{path}\{filename}.exe"
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- {random} = "{path}\{filename}.exe"
- {random} = "{path}\{filename}.exe"
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_VUNDO.XPBL. 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.
Step 7
The following created files/folders/registry keys/registry entries cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present system information with a backup. Note that the said components do not have to be deleted since it won't be harmful to the system.
- HKEY_LOCAL_MACHINE\SOFTWARE\{random 1}
- {random 2} = "{random values}"
- {random 2} = "{random values}"
- In HKEY_CURRENT_USER\SOFTWARE\{random 1}
- {random 2} = "{random values}"
- {random 2} = "{random values}"
Step 8
Scan your computer with your Trend Micro product to delete files detected as TROJ_VUNDO.XPBL. 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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