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TROJ_TREDPAF.A

November 16, 2013
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • 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

File Size:

293,376 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

29 Oct 2013

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\HTTP\Parameters\
Synchronize

Other System Modifications

This Trojan modifies the following file(s):

  • %User Profile%\Application Data\Microsoft

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
Synchronize\SSL

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
F23719760008D5B5A8E865FA498961AF13628113

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
SslBindingInfo\0.0.0.0:443

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
F23719760008D5B5A8E865FA498961AF13628113
Blob = "{random values}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
SslBindingInfo\0.0.0.0:443
SslCertHash = "{random values}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
SslBindingInfo\0.0.0.0:443
AppId = "{random values}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
SslBindingInfo\0.0.0.0:443
DefaultSslCertCheckMode = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
SslBindingInfo\0.0.0.0:443
DefaultSslRevocationFreshnessTime = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
SslBindingInfo\0.0.0.0:443
DefaultSslRevocationUrlRetrievalTimeout = "271"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
SslBindingInfo\0.0.0.0:443
DefaultFlags = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HTTP\Parameters\
SslBindingInfo\0.0.0.0:443
SslCertStoreName = "ROOT"

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\Microsoft\Crypto
  • %User Profile%\Crypto\RSA
  • %User Profile%\RSA\MachineKeys
  • \Device\Http\AppPool
  • \Device\Http\Filter\SSLFilterChannel

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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

[ Learn More ]

Step 3

Delete this registry key

[ 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\HTTP\Parameters
    • Synchronize
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\Synchronize
    • SSL
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates
    • F23719760008D5B5A8E865FA498961AF13628113
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\SslBindingInfo
    • 0.0.0.0:443

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\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates\F23719760008D5B5A8E865FA498961AF13628113
    • Blob = "{random values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\SslBindingInfo\0.0.0.0:443
    • SslCertHash = "{random values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\SslBindingInfo\0.0.0.0:443
    • AppId = "{random values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\SslBindingInfo\0.0.0.0:443
    • DefaultSslCertCheckMode = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\SslBindingInfo\0.0.0.0:443
    • DefaultSslRevocationFreshnessTime = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\SslBindingInfo\0.0.0.0:443
    • DefaultSslRevocationUrlRetrievalTimeout = "271"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\SslBindingInfo\0.0.0.0:443
    • DefaultFlags = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\HTTP\Parameters\SslBindingInfo\0.0.0.0:443
    • SslCertStoreName = "ROOT"

Step 5

Search and delete these components

[ Learn More ]
There may be some components that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Profile%\Microsoft\Crypto
  • %User Profile%\Crypto\RSA
  • %User Profile%\RSA\MachineKeys
  • \Device\Http\AppPool
  • \Device\Http\Filter\SSLFilterChannel

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_TREDPAF.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.

Step 7

Restore deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    • %User Profile%\Application Data\Microsoft


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