TROJ_AMBLER.KB
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This Trojan may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.
It deletes itself after execution.
TECHNICAL DETAILS
Arrival Details
This Trojan may be downloaded by other malware/grayware/spyware from remote sites.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This Trojan drops the following files:
- %User Profile%\Application Data\fkhneec.dll or %User Profile%\Application Data\fzetuvdo79.dll -TSPY_AMBLER.KB
- %User Profile%\Application Data\Sun\wsfxq
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It creates the following folders:
- %User Profile%\Application Data\Sun
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
Autostart Technique
This Trojan creates the following registry entries to enable automatic execution of dropped component at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
lpc = rundll32.exe %User Profile%\Application Data\Sun\{fkhneec.dll or fzetuvdo79.dll}, RegisterDll
Other System Modifications
This Trojan deletes the following files:
- %User Profile%\Application Data\Sun\rwbbr.txt
- %User Profile%\Application Data\Sun\oietr.txt
- %User Profile%\Application Data\Sun\cngrh.txt
- %User Profile%\Application Data\Sun\vntw.txt
- %User Profile%\Application Data\Sun\mogr.txt
- %User Profile%\Application Data\Sun\cetw.txt
- %User Profile%\Application Data\Sun\mxd1.txt
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Clock
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Clock
D1 = 79 74 7d 71 7c 62 7c 74 66 64 70 78 26 76 73 3a 7c 78 72 7a 39 7a 70 61 72 7a 7a 70 70 64
HKEY_CURRENT_USER\Software\Microsoft\
Clock
D2 = 66 70 65 26
HKEY_CURRENT_USER\Software\Microsoft\
Clock
D3 = 66 70 65 27
HKEY_CURRENT_USER\Software\Microsoft\
Clock
pr = 7c 61 62 64 2f 39 3b 6f 7e 7b 72 72 7d 74 78 75 3b 7f 7a 73 79 3b 7b 73 63 73 79 78 71 73 66
Other Details
This Trojan deletes itself after execution.
SOLUTION
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
Remove malware files dropped/downloaded by TROJ_AMBLER.KB
- TSPY_AMBLER.KB
Step 3
Delete this registry key
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
- Clock
- Clock
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- lpc = rundll32.exe %User Profile%\Application Data\Sun\{fkhneec.dll or fzetuvdo79.dll}, RegisterDll
- lpc = rundll32.exe %User Profile%\Application Data\Sun\{fkhneec.dll or fzetuvdo79.dll}, RegisterDll
Step 5
Search and delete these folders
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_AMBLER.KB. 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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