arrow_back
search
close

TROJ_BIFROSE.USB13VC

October 12, 2012
 ALIASES:

Trojan:Win32/Malagent (Microsoft); Generic.dx!bczz (McAfee); Trojan.Gen.2 (Symantec); Trojan-Dropper.Win32.Dapato.adao (Kaspersky); Trojan.Win32.Generic!BT (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.

It disables Task Manager, Registry Editor, and Folder Options.

  TECHNICAL DETAILS

File Size:

447,992 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

07 Mar 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.

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
RHKCUM = "%User Profile%\Application Data\ptrspoolr.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
RHKCUP = "%User Profile%\Application Data\ptrspl.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
RHKCUV = "%User Profile%\Application Data\ptrsplr.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{O77KY2JI-LRCH-344T-EN4Q-OP0V2WT50KU1}
StubPath = "%User Temp%\ptrspl.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\SOFTWARE\Ossy

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\MediaResources\msvideo

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run

HKEY_LOCAL_MACHINE\Software\Microsoft\
Active Setup\Installed Components\{O77KY2JI-LRCH-344T-EN4Q-OP0V2WT50KU1}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Ossy
FirstExecution = "16/02/2012 -- 09:13"

HKEY_CURRENT_USER\Software\Ossy
NewIdentification = "Ossy"

HKEY_CURRENT_USER\Software\Ossy
NewGroup = [REG_EXPAND_SZ, value: ]

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
Policies = "%User Temp%\ptrspl.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\advapi32.dll[MofResourceName] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\mssmbios.sys[MofResource] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ipnat.sys[IPNATMofResource] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\Drivers\HTTP.sys[UlMofResource] = "{random characters}"

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
Policies = "%User Temp%\ptrspl.exe"

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\{O77KY2JI-LRCH-344T-EN4Q-OP0V2WT50KU1}

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\Application Data\ptrspoolr.exe
  • %User Temp%\ptrsplrr.exe
  • %User Temp%\ptrspl.exe
  • %User Profile%\Application Data\ptrsplr.exe
  • %User Profile%\Application Data\ptrspl.exe
  • %User Temp%\Administrator2.txt
  • %User Profile%\Application Data\Administratorv1.20.10Ossylog.dat
  • %User Temp%\Administrator7
  • %User Temp%\Administrator8
  • %User Profile%\Application Data\Administratorv1.20.10.vbs

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %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.)

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

Enable Registry Editor, Task Manager, and Folder options

[ Learn More ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware.

Step 4

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
    • Ossy
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources
    • msvideo
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • Run
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components
    • {O77KY2JI-LRCH-344T-EN4Q-OP0V2WT50KU1}

Step 5

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
    • RHKCUM = "%User Profile%\Application Data\ptrspoolr.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • RHKCUP = "%User Profile%\Application Data\ptrspl.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • RHKCUV = "%User Profile%\Application Data\ptrsplr.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{O77KY2JI-LRCH-344T-EN4Q-OP0V2WT50KU1}
    • StubPath = "%User Temp%\ptrspl.exe"
  • In HKEY_CURRENT_USER\Software\Ossy
    • FirstExecution = "16/02/2012 -- 09:13"
  • In HKEY_CURRENT_USER\Software\Ossy
    • NewIdentification = "Ossy"
  • In HKEY_CURRENT_USER\Software\Ossy
    • NewGroup = [REG_EXPAND_SZ, value: ]
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
    • Policies = "%User Temp%\ptrspl.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\advapi32.dll[MofResourceName] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\DRIVERS\mssmbios.sys[MofResource] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\DRIVERS\ipnat.sys[IPNATMofResource] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\Drivers\HTTP.sys[UlMofResource] = "{random characters}"

Step 6

Search and delete these files

[ Learn More ]
There may be some component 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.
  • %User Profile%\Application Data\ptrspoolr.exe
  • %User Temp%\ptrsplrr.exe
  • %User Temp%\ptrspl.exe
  • %User Profile%\Application Data\ptrsplr.exe
  • %User Profile%\Application Data\ptrspl.exe
  • %User Temp%\Administrator2.txt
  • %User Profile%\Application Data\Administratorv1.20.10Ossylog.dat
  • %User Temp%\Administrator7
  • %User Temp%\Administrator8
  • %User Profile%\Application Data\Administratorv1.20.10.vbs

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_BIFROSE.USB13VC. 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 8

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_CURRENT_USER\Software\Microsoft\Active Setup\Installed Components
    • {O77KY2JI-LRCH-344T-EN4Q-OP0V2WT50KU1}


Did this description help? Tell us how we did.