TROJ_YAKES.KLS
Windows
![](/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
593,190 bytes
EXE
Yes
19 Feb 2015
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.
Autostart Technique
This Trojan registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\AojaobE
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\AojaobE\Parameters
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\1702~1.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.)
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AojaobE
ImagePath = "%SystemRoot%\System32\svchost.exe -k netsvcs"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AojaobE
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AojaobE
DisplayName = "AojaobE"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AojaobE
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AojaobE
ErrorControl = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AojaobE
Type = "2"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AojaobE
Description = "Manages Miniport ability generic selected."
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AojaobE\Parameters
ServiceDll = "%System%\vbowbni.dll"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
netsvcs = "{random characters}"
(Note: The default value data of the said registry entry is {random values}.)
Dropping Routine
This Trojan drops the following files:
- %User Temp%\names.txt
- %User Temp%\17.02.exe
- %User Temp%\tn.jpg
- %System%\vbowbni.dll
(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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
Other Details
This Trojan connects to the following possibly malicious URL:
- {BLOCKED}.3.180
This report is generated via an automated analysis system.
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
Restart in Safe Mode
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_LOCAL_MACHINE\System\CurrentControlSet\Services
- AojaobE
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\AojaobE
- Parameters
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\SYSTEM\ControlSet001\Services\AojaobE
- ImagePath = "%SystemRoot%\System32\svchost.exe -k netsvcs"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AojaobE
- ObjectName = "LocalSystem"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AojaobE
- DisplayName = "AojaobE"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AojaobE
- Start = "2"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AojaobE
- ErrorControl = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AojaobE
- Type = "2"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AojaobE
- Description = "Manages Miniport ability generic selected."
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AojaobE\Parameters
- ServiceDll = "%System%\vbowbni.dll"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
- From: netsvcs = "{random characters}"
To: netsvcs = ""{random values}""
- From: netsvcs = "{random characters}"
Step 6
Search and delete these components
- %User Temp%\names.txt
- %User Temp%\17.02.exe
- %User Temp%\tn.jpg
- %System%\vbowbni.dll
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_YAKES.KLS. 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 8
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %User Temp%\1702~1.EXE
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