RTKT64_KERLISEN.A

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.

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.