Analysis by: Christopher Daniel So
ALIASES:

Worm:Win32/Pushbot.gen!C (Microsoft), RDN/Checkout!a (McAfee), Hacktool.Rootkit (Symantec), IM-Worm.Win32.Yahos.db (Kaspersky), W32/Jorik_Lolbot.DL!tr (Fortinet), Worm.Win32.Pushbot (Ikarus), Win32/Boberog.AZ worm (ESET), Trojan.Win32.Generic!BT (Sunbelt)

 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: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Propagates via removable drives, Downloaded from the Internet, Dropped by other malware

This worm arrives via removable drives. It 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: 41,984 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 10 Apr 2014
Payload: Drops files

Arrival Details

This worm arrives via removable drives.

It 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 worm drops the following copies of itself into the affected system:

  • %Application Data%\HEX-5823-6893-6818\jutched.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.)

It creates the following folders:

  • %Application Data%\HEX-5823-6893-6818

(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.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • l0lkn0lltr0ll

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Java Update Manager = "%Application Data%\HEX-5823-6893-6818\jutched.exe"

Other System Modifications

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Application Data%\HEX-5823-6893-6818\jutched.exe = "%Application Data%\HEX-5823-6893-6818\jutched.exe:*:Enabled:Java Update Manager"

Propagation

This worm creates the following folders in all removable drives:

  • {removable drive letter}:\8585485

NOTES:

It drops copies of itself in the folder {removable drive letter}:\8585485 with the names of the folders in {removable drive letter}:\. It then drops .LNK files with the names of the folders in the root folder of the removable drive that point to the dropped malware copies in {removable drive letter}:\8585485.

It terminates itself if seven (7) of the following do not exist in the system:

  • %System%\ntkrnlpa.exe
  • %System%\telnet.exe
  • %System%\systray.exe
  • %System%\tasklist.exe
  • %System%\charmap.exe
  • %System%\shadow.exe
  • %System%\sfc.exe
  • %System%\winspool.exe
  • %System%\ntvdm.exe

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 7.718.01
FIRST VSAPI PATTERN DATE: 10 Apr 2014

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

Identify and terminate files detected as WORM_PUSHBOT.TAF

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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\Microsoft\Windows\CurrentVersion\Run
    • Java Update Manager = "%Application Data%\HEX-5823-6893-6818\jutched.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Application Data%\HEX-5823-6893-6818\jutched.exe = "%Application Data%\HEX-5823-6893-6818\jutched.exe:*:Enabled:Java Update Manager"

Step 4

Search and delete these folders

[ 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.
  • %Application Data%\HEX-5823-6893-6818
  • {removable drive letter}:\8585485

Step 5

Scan your computer with your Trend Micro product to delete files detected as WORM_PUSHBOT.TAF. 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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