ALIASES:

Trojan:Win32/AproposMedia (Microsoft); Adware-Apropos. (McAfee); Spyware.Apropos (Symantec); Trojan-Downloader.Win32.Apropo.e (Kaspersky); AproposMedia.ContextPlus (Sunbelt); Trojan.Downloader.Apropo.E (FSecure)

 PLATFORM:

Windows 2000, XP, 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: 76,341 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 13 Nov 2011

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 adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
AutoLoaderAproposClient = ""{malware path and file name}" "

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\auf0.exe

(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.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\AutoLoader\
AproposClient

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
LoadUrl = "http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/<>/AproposClientInstaller.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
TempFile = "%User Temp%\auf0.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 1

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 1

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 1

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 2

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 2

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Downloaded = 1

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 2

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 3

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 3

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 3

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 4

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 4

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 4

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 5

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 5

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 5

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 6

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 6

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 6

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 7

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 7

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 7

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 8

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 8

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 8

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = 9

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = 9

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = 9

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = a

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = a

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = a

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Total = b

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Attempts = b

HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\
AproposClient
Trust = b

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/1/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/2/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/3/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/4/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/5/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/6/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/7/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/8/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/9/AproposClientInstaller.exe
  • http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/10/AproposClientInstaller.exe

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.200

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

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\Software\AutoLoader
    • AproposClient

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\Windows\CurrentVersion\Run
    • AutoLoaderAproposClient=""{malware path and file name}" "
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • LoadUrl="http://download.{BLOCKED}lligence.net/apropos/client/AM.POP/<>/AproposClientInstaller.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • TempFile="%User Temp%\auf0.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Downloaded=1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=3
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=3
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=3
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=4
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=4
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=4
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=5
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=5
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=5
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=6
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=6
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=6
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=7
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=7
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=7
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=8
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=8
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=8
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=9
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=9
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=9
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=a
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=a
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=a
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Total=b
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Attempts=b
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AutoLoader\AproposClient
    • Trust=b

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_APROPO.E. 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 6

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again. %User Temp%\auf0.exe


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