Author: Arjun Bryan Baltazar   

 

Trojan.Pandemiya (Symantec) , TrojanSpy:Win32/Ursnif (Microsoft) , Trojan-Spy.Win32.Ursnif.tyj (Kaspersky)

 PLATFORM:

Windows

 OVER ALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE
Low
Medium
High
Critical

  • Threat Type:
    Trojan Spy

  • Destructiveness:
    No

  • Encrypted:
    Yes

  • In the wild:
    Yes

  OVERVIEW

INFECTION CHANNEL: Dropped by other malware, Downloaded from the Internet

This Trojan Spy arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File size: 753,664 bytes
File type: EXE
Memory resident: Yes
INITIAL SAMPLES RECEIVED DATE: 21 September 2017
PAYLOAD: Connects to URLs/IPs, Steals information, Compromises system security

Arrival Details

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

  • %Application Data%\{string1}{string2}\{string1}{string2}.exe
      where:
    • {string1} = first four letters of a dll file under System directory
    • {string2} = last four letters of a dll file under System directory

(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, 7, and 8.)

It drops and executes the following files:

  • %User Temp%\{random folder name}\{random filename}.bat ← used to delete itself; deleted afterwards

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

It injects codes into the following process(es):

  • explorer.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{string1}{string2} = "%Application Data%\{string1}{string2}\{string1}{string2}.exe"

Other System Modifications

This Trojan Spy adds the following registry keys:

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Vars =

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Files =

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
Config =

It adds the following registry entries:

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
{UID} = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\{GUID}
{Value Name} = "{data}"

  • where {Value Name} may be any of the following:
    • Main
    • Block
    • Temp
    • Client
    • Ini
    • Keys
    • Scr
    • LastTask
    • LastConfig
    • CrHook
    • OpHook
    • Exec
    • TorClient
    • TorCrc
    • Install

    Dropping Routine

    This Trojan Spy drops the following files wherein it saves the information it gathers:

    • %User Temp%\{random filename}.bin

    (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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

    Information Theft

    This Trojan Spy gathers the following data:

    • Key Board Logs
    • Clipboard Logs
    • Running processes and services

    Other Details

    This Trojan Spy connects to the following website to send and receive information:

    • http://{BLOCKED}unfvjdn.net/images/{RANDOM PATH}
    • http://{BLOCKED}ebncxds.com/images/{RANDOM PATH}

    It does the following:

    • Saves stolen information in a file and then uploads it.
    • Monitors Internet browsing activities.
    • Hooks APIs of target process.
    • Disables SPDY protocol
    • It terminates itself if it runs under a virtual machine or sandbox by checking the following strings against Plug and Play devices:
      • vbox
      • qemu
      • vmware
      • virtual hd
    • It executes the following commands:
      • cmd.exe /C "%Application Data%\{string1}{string2}\{string1}{string2}.exe" "{Executed Malware Directory}"

    (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, 7, and 8.)

      SOLUTION

    Minimum scan engine: 9.850
    First VSAPI Pattern File: 13.674.03
    First VSAPI Pattern Release Date: 22 September 2017
    VSAPI OPR PATTERN-VERSION: 13.675.00
    VSAPI OPR PATTERN DATE: 23 September 2017

    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

    Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

    Step 3

    Restart in Safe Mode

    [ learnMore ]

    Step 4

    Delete this registry value

    [ learnMore ]

    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\AppDataLow\Software\Microsoft\{GUID}
      • {UID} = "{hex value}"
    • In HKEY_CURRENT_USER\Software\AppDataLow\Software\Microsoft\{GUID}
      • {Value Name} = "{data}"

    Step 5

    Delete this registry key

    [ learnMore ]

    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
      • {string1}{string2} = "%Application Data%\{string1}{string2}\{string1}{string2}.exe"
    • In HKEY_CURRENT_USER\Software\AppDataLow\Software\Microsoft
      • {GUID}

    Step 6

    Search and delete this file

    [ learnMore ]
    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.
    • %Application Data%\{string1}{string2}\{string1}{string2}.exe
    • where:
    • {string1} = first four letters of a dll file under System directory
    • {string2} = last four letters of a dll file under System directory
    • %User Temp%\{random folder name}\{random filename}.bat
    • %User Temp%\{random filename}.bin

    Step 7

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