RTKT64_KERLISEN.A
Rootkit.Win64.Winnti.p (Kaspersky)
Windows 2000, Windows Server 2003, Windows XP (64-bit), Windows Vista (64-bit), Windows 7 (64-bit)
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 does not have any propagation routine.
It does not have any backdoor routine.
It does not have any downloading capability.
It does not have any information-stealing capability.
TECHNICAL DETAILS
61,168 bytes
SYS
Yes
23 Apr 2014
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 itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}
DisplayName = "{malware filename}"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}
ImagePath = "{malware path and filename}"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}
Start = "3"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}
Type = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}
WOW64 = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}
ErrorControl = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000\Control
*NewlyCreated* = "0"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000\Control
ActiveService = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
Class = "LegacyDriver"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
ClassGUID = "{GUID}"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
ConfigFlags = "0"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
DeviceDesc = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
Legacy = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
Service = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}\Enum
{number} = "Root\LEGACY_{malware filename}\0000"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}\Enum
Count = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{malware filename}\Enum
NextInstance = "1"
It 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\{malware filename}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}
Propagation
This Trojan does not have any propagation routine.
Backdoor Routine
This Trojan does not have any backdoor routine.
Download Routine
This Trojan does not have any downloading capability.
Information Theft
This Trojan does not have any information-stealing capability.
NOTES:
This is a callout driver which is used to add filter on tcp/ip based network.
It uses RtlGetVersion to get the version of the system.
If the system is older than Windows Vista:
It will hook the following tcpip.sys functions:
- IPInjectPkt
- IpAllocBuff
- IpFreeBuff
If the system is Windows Vista and higher:
- ndis.sys functions are used for Windows Filtering Platform
The callout driver creates the following callout filters:
- CalloutIn
- CalloutOut
- CalloutListen
- CalloutAccept
- CalloutResource
It requires the following additional component file:
- TSVIPSrv.dll
It does not exploit any vulnerability.
SOLUTION
9.700
10.746.03
23 Apr 2014
10.747.00
24 Apr 2014
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
Scan your computer with your Trend Micro product and note files detected as RTKT64_KERLISEN.A
Step 3
Restart in Safe Mode
Step 4
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- {malware filename}
- {malware filename}
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root
- LEGACY_{malware filename}
- LEGACY_{malware filename}
Step 5
Search and delete this file
- TSVIPSrv.dll
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RTKT64_KERLISEN.A. 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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