ALIASES:

Exploit:Win32/Wmfap.A (Microsoft); Generic.dh (McAfee); W32.Spybot.Worm (Symantec); Backdoor.IRCBot (Sunbelt); Generic.Malware.IFWX!Bprng.99109070 (FSecure)

 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: 937,984 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 30 Nov 2012

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.

Installation

This Trojan drops the following copies of itself into the affected system:

  • %System%\explorer.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Licenses

HKEY_CLASSES_ROOT\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}\InProcServer32

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{R7C0DB872A3F777C0} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{K7C0DB872A3F777C0} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}\InProcServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{I2E5BF379E4283A1D} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{02E5BF379E4283A1D} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
mpjzgD = "mvjsFKO[blwOcZeLmZ]"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
wscIeLtxnpz = "CbE\bC\ptwuQTdMXKSdOZM"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
OINKjCqtxZm = "kKpUTYPhp[\uKv}Q^Z^niC]QcMX"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
qjzl = "_w`pbEA~smXi@p^AYob}dNYz`LIl[A"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
xJDo = "wbfkvTQDDp[GQqQmHTG}}d{zHmmAD}@"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
krFdPKaPk = "uJzAx^YUCymGsPvJnLL["

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
xJDo = "wbVkvTQDD@[GQqQmHTG}}d{zHmmAD}@"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
krFdPKaPk = "uJzAx^YUCImGsPtoe{ar"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
xJDo = "wbFkvTQDDP[GQqQmJDG}}d{zHmmAD}@"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
krFdPKaPk = "uJzAx^YU@ymGsPw`Y{oG"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
krFdPKaPk = "uJzAx^YU@ImGsPtpGQn@"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
krFdPKaPk = "uJzAx^YUCYmGsPv_omaO"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
xJDo = "wbFkvTQDDP[GQqQmHTG}}d{zHmmAD}@"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
krFdPKaPk = "uJzAx^YU@imGsPvbyqEa"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
RFC1156Agent\CurrentVersion\Parameters
TrapPollTimeMilliSecs = "3a98"

(Note: The default value data of the said registry entry is 3a98.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}\Version

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\63F7B3FB.TMP
  • %Temp%\63F7B3FB.TMP

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

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

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\Software
    • Licenses
  • In HKEY_CLASSES_ROOT\CLSID
    • {3753AE44-0B5B-9C57-3753-AE443753AE44}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • InProcServer32

Step 3

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\Licenses
    • {R7C0DB872A3F777C0} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
    • {K7C0DB872A3F777C0} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}\InProcServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
    • {I2E5BF379E4283A1D} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
    • {02E5BF379E4283A1D} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • mpjzgD = "mvjsFKO[blwOcZeLmZ]"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • wscIeLtxnpz = "CbE\bC\ptwuQTdMXKSdOZM"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • OINKjCqtxZm = "kKpUTYPhp[\uKv}Q^Z^niC]QcMX"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • qjzl = "_w`pbEA~smXi@p^AYob}dNYz`LIl[A"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • xJDo = "wbfkvTQDDp[GQqQmHTG}}d{zHmmAD}@"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • krFdPKaPk = "uJzAx^YUCymGsPvJnLL["
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • xJDo = "wbVkvTQDD@[GQqQmHTG}}d{zHmmAD}@"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • krFdPKaPk = "uJzAx^YUCImGsPtoe{ar"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • xJDo = "wbFkvTQDDP[GQqQmJDG}}d{zHmmAD}@"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • krFdPKaPk = "uJzAx^YU@ymGsPw`Y{oG"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • krFdPKaPk = "uJzAx^YU@ImGsPtpGQn@"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • krFdPKaPk = "uJzAx^YUCYmGsPv_omaO"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • xJDo = "wbFkvTQDDP[GQqQmHTG}}d{zHmmAD}@"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • krFdPKaPk = "uJzAx^YU@imGsPvbyqEa"

Step 4

Restore these modified registry values

[ Learn More ]

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\RFC1156Agent\CurrentVersion\Parameters
    • From: TrapPollTimeMilliSecs = "3a98"
      To: TrapPollTimeMilliSecs = ""3a98""

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 Temp%\63F7B3FB.TMP
  • %Temp%\63F7B3FB.TMP

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_AGOBOT.AX. 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 these deleted registry keys/values from backup

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

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3753AE44-0B5B-9C57-3753-AE443753AE44}
    • Version


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