BKDR_ALDIBOT.B

 Analysis by: Rika Joi Gregorio

 ALIASES:

DDoS:Win32/Abot.A(Microsoft), Trojan.Win32.Abot(Ikarus)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • 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. It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size:

127,488 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

21 Aug 2013

Payload:

Compromises system security, Connects to URLs/IPs, Steals information

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.

Installation

This backdoor drops the following copies of itself into the affected system and executes them:

  • %Application Data%\hklm.exe

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

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
c0xG3w0pwDWmTic = "%Application Data%\hklm.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
c0xG3w0pwDWmTic = "%Application Data%\hklm.exe"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{random}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{random}
Audio Treiber x64 = ""%Application Data%\AudioTreiber_x64.exe /ActiveX""

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Application Data%\hklm.exe = "%Application Data%\hklm.exe:*:Enabled:"

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • StartHTTP - starts an HTTP DDoS attack
  • StartTCP - starts a TCP DDoS attack
  • StopHTTPDDoS - stops an HTTP DDoS attack
  • StopTCPDDoS - stops a TCP DDoS attack
  • StopDDoS - stops all DDoS attack
  • DownloadEx - downloads and executes file
  • CreateSocks - creates SOCKS5 proxy
  • StealData - performs password stealing capability
  • Update - updates itself

It connects to the following websites to send and receive information:

  • http://{BLOCKED}1.{BLOCKED}a.funpic.de/aldi/gate.php?hwid={HWID}&pc={Host Name}&localip={Local IP Address}&winver={OS Version}

Information Theft

This backdoor gathers the following data:

  • Hardware Identification (HWID)
  • Host Name
  • Local IP Address
  • OS Version

It attempts to get stored information such as user names, passwords, and hostnames from the following browsers:

  • Mozilla Firefox

NOTES:

It steals information such as user names and passwords from the following application:

  • Pidgin
  • jDownloader

It also uses the following as its User-Agent:

  • Aldi Bot FTW :D

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

10.230.02

FIRST VSAPI PATTERN DATE:

21 Aug 2013

VSAPI OPR PATTERN File:

10.231.00

VSAPI OPR PATTERN Date:

22 Aug 2013

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\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {random}

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • c0xG3w0pwDWmTic = "%Application Data%\hklm.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • c0xG3w0pwDWmTic = "%Application Data%\hklm.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Application Data%\hklm.exe = "%Application Data%\hklm.exe:*:Enabled:"

Step 5

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


Did this description help? Tell us how we did.