Analysis by: Rika Joi Gregorio
ALIASES:

TrojanSpy:Win32/Ursnif.gen!P(Microsoft), W32/Papras.DS!tr.pws(Fortinet), Win32/PSW.Papras.DS trojan(NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This spyware 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. It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 336,216 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 02 Mar 2015
Payload: Steals information, Connects to URLs/IPs

Arrival Details

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

  • %System%\{random file name}.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

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

  • Local\{GUID}

It injects codes into the following process(es):

  • explorer.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = "%System%\{random file name}.exe"

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\AppDataLow\
{GUID}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\AppDataLow\
{GUID}
Install = "{hex value}"

HKEY_CURRENT_USER\Software\AppDataLow\
{GUID}
Client = "{hex value}"

Information Theft

This spyware gathers the following data:

  • Digital Certificates
  • Capture Screenshot
  • Computer Name
  • List Processes
  • List Contents on this registry: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\
  • System Information
  • Steal Cookies
  • List Drivers

Other Details

This spyware connects to the following website to send and receive information:

  • http://{BLOCKED}repport.su/zzz_img/flib/xxx/

It deletes itself after execution.

NOTES:

It locates the following registries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Antimalware\Exclusions\Paths
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Exclusions\Paths

If found, it adds the following registry to exclude its dropped copy everytime an antivirus performs a scan:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Antimalware\Exclusions\Paths %System%\{random file name}.exe = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Exclusions\Paths %System%\{random file name}.exe = "0"

It also terminates itself once found running in the following environment:

  • vbox
  • qemu
  • vmware
  • virtual hd

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.518.03
FIRST VSAPI PATTERN DATE: 04 Mar 2015
VSAPI OPR PATTERN File: 11.519.00
VSAPI OPR PATTERN Date: 05 Mar 2015

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

[ Learn More ]

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\AppDataLow
    • {GUID}

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
    • {random} = "%System%\{random file name}.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Antimalware\Exclusions\Paths
    • %System%\{random file name}.exe = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Exclusions\Paths
    • %System%\{random file name}.exe = "0"

Step 6

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