BKDR_FAKEAP.MST

December 16, 2014
 Analysis by: Jaime Benigno Reyes
 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

04 Dec 2014

Payload:

Compromises system security

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Other System Modifications

This backdoor creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\SharedAccess\Parameters\
FirewallPolicy\FirewallRules
{random GUID} = "v{version number}|Action=Allow|Active=TRUE|Dir=In|Protocol=6|LPort=7480|Name=Trend|" (Windows Vista and higher versions and if executed as administrator)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\SharedAccess\Parameters\
FirewallPolicy\FirewallRules
TCP Query User{random GUID}{malware location}\{malware name} = "v{version number}|Action=Allow|Active=TRUE|Dir=In|Protocol=6|Profile=Public|App={malware location}\{malware name}|Name={malware filename}|Desc={malware filename}|Defer=User|" (Windows Vista and higher versions and if user allowed access)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\SharedAccess\Parameters\
FirewallPolicy\FirewallRules
UDP Query User{random GUID}{malware location}\{malware name} = "v{version number}|Action=Allow|Active=TRUE|Dir=In|Protocol=17|Profile=Public|App={malware location}\{malware name}|Name={malware filename}|Desc={malware filename}|Defer=User|" (Windows Vista and higher versions and if user allowed access)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\SharedAccess\Parameters\
FirewallPolicy\FirewallRules
TCP Query User{random GUID}{malware location}\{malware name} = "v{version number}|Action=Block|Active=TRUE|Dir=In|Protocol=6|Profile=Public|App={malware location}\{malware name}|Name={malware filename}|Desc={malware filename}|" (Windows Vista and higher versions and if user blocked access)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\SharedAccess\Parameters\
FirewallPolicy\FirewallRules
UDP Query User{random GUID}{malware location}\{malware name} = "v{version number}|Action=Block|Active=TRUE|Dir=In|Protocol=17|Profile=Public|App={malware location}\{malware name}|Name={malware filename}|Desc={malware filename}|" (Windows Vista and higher versions and if user blocked access)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware location}\{malware name} = "{malware location}\{malware name}:*:Enabled:{malware filename}" (Versions lower than Windows Vista and if user allowed access)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware location}\{malware name} = "{malware location}\{malware name}:*:Disabled:{malware filename}" (Versions lower than Windows Vista and if user blocked access)

Backdoor Routine

This backdoor opens the following port(s) where it listens for remote commands:

  • 7480

It executes the following commands from a remote malicious user:

  • perform remote shell commands
  • send result of performed shell commands
  • download and execute arbitrary files

NOTES:

The registry entries mentioned above are added after this malware performs the following command:

  • netsh advfirewall firewall add rule name=Trend protocol=TCP dir=in localport=7480 action=allow

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

11.320.02

FIRST VSAPI PATTERN DATE:

05 Dec 2014

VSAPI OPR PATTERN File:

11.321.00

VSAPI OPR PATTERN Date:

05 Dec 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

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

Identify and terminate files detected as BKDR_FAKEAP.MST

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Delete this registry value

[ Learn More ]

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\SharedAccess\Parameters\FirewallPolicy\FirewallRules
    • {random GUID} = "v{version number}|Action=Allow|Active=TRUE|Dir=In|Protocol=6|LPort=7480|Name=Trend|" (Windows Vista and higher versions and if executed as administrator)
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SharedAccess\Parameters\FirewallPolicy\FirewallRules
    • TCP Query User{random GUID}{malware location}\{malware name} = "v{version number}|Action=Allow|Active=TRUE|Dir=In|Protocol=6|Profile=Public|App={malware location}\{malware name}|Name={malware filename}|Desc={malware filename}|Defer=User|" (Windows Vista and higher versions and if user allowed access)
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SharedAccess\Parameters\FirewallPolicy\FirewallRules
    • UDP Query User{random GUID}{malware location}\{malware name} = "v{version number}|Action=Allow|Active=TRUE|Dir=In|Protocol=17|Profile=Public|App={malware location}\{malware name}|Name={malware filename}|Desc={malware filename}|Defer=User|" (Windows Vista and higher versions and if user allowed access)
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SharedAccess\Parameters\FirewallPolicy\FirewallRules
    • TCP Query User{random GUID}{malware location}\{malware name} = "v{version number}|Action=Block|Active=TRUE|Dir=In|Protocol=6|Profile=Public|App={malware location}\{malware name}|Name={malware filename}|Desc={malware filename}|" (Windows Vista and higher versions and if user blocked access)
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SharedAccess\Parameters\FirewallPolicy\FirewallRules
    • UDP Query User{random GUID}{malware location}\{malware name} = "v{version number}|Action=Block|Active=TRUE|Dir=In|Protocol=17|Profile=Public|App={malware location}\{malware name}|Name={malware filename}|Desc={malware filename}|" (Windows Vista and higher versions and if user blocked access)
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • {malware location}\{malware name} = "{malware location}\{malware name}:*:Enabled:{malware filename}" (Versions lower than Windows Vista and if user allowed access)
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • {malware location}\{malware name} = "{malware location}\{malware name}:*:Disabled:{malware filename}" (Versions lower than Windows Vista and if user blocked access)

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_FAKEAP.MST. 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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