TROJ_DIALER.AAB

April 26, 2013
 ALIASES:

Dialer:Win32/Adialer (Microsoft); Dialer-Generic. (McAfee); Dialer.Trafficjam (Symantec); Dialer.Win32.Agent.b (Kaspersky); Trojan.Win32.Packer.PESpinv1.304 (ep) (Sunbelt)

 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:

52,224 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

26 Apr 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.

Installation

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

  • %Program Files%\Common Files\delsim\del.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

It creates the following folders:

  • %Program Files%\Common Files\delsim

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Delsim\
Connection\del

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
delsim

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Delsim\
Connection\del
uninstExe = "%Program Files%\Common Files\delsim\del.exe"

HKEY_CURRENT_USER\Software\Delsim\
Connection\del
uninstShortcut = "%Start Menu%\del.lnk"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
delsim
DisplayName = "Delsim Dialer"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
delsim
UninstallString = "%Program Files%\Common Files\delsim\del.exe -u"

HKEY_CURRENT_USER\Software\Delsim\
Connection\del
Default = "„è‰"

Dropping Routine

This Trojan drops the following files:

  • %Start Menu%\del.lnk

(Note: %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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

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_CURRENT_USER\Software\Delsim\Connection
    • del
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
    • delsim

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_CURRENT_USER\Software\Delsim\Connection\del
    • uninstExe = "%Program Files%\Common Files\delsim\del.exe"
  • In HKEY_CURRENT_USER\Software\Delsim\Connection\del
    • uninstShortcut = "%Start Menu%\del.lnk"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\delsim
    • DisplayName = "Delsim Dialer"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\delsim
    • UninstallString = "%Program Files%\Common Files\delsim\del.exe -u"
  • In HKEY_CURRENT_USER\Software\Delsim\Connection\del
    • Default = "„è‰"

Step 4

Search and delete this file

[ Learn More ]
There may be some files 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.
  • %Start Menu%\del.lnk

Step 5

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Program Files%\Common Files\delsim

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_DIALER.AAB. 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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