Analysis by: Janus Agcaoili
ALIASES:

Trojan.PWS.Papras.1637 (DrWeb), Trojan.Win32.Papras.dzoagk (NANO-Antivirus), Win32/PSW.Papras.EH (ESET-NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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 deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 332,288 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 14 Jan 2016

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:

  • %Application Data%\api-svc6\AppIwcfg.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It drops and executes the following files:

  • %User Temp%\{random string}\{random string}.bat

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

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
api-perf = "%Application Data%\api-svc6\AppIwcfg.exe"

Other System Modifications

This spyware adds the following registry entries:

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\(GUID)
Install = "{hex values}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\(GUID)
{GUID 2} = "{hex values}"

HKEY_CURRENT_USER\Software\AppDataLow\
Software\Microsoft\(GUID)
Client = "{hex values}"

Other Details

This spyware deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.272.03
FIRST VSAPI PATTERN DATE: 14 Jan 2016
VSAPI OPR PATTERN File: 12.273.00
VSAPI OPR PATTERN Date: 15 Jan 2016

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 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
    • api-perf = "%Application Data%\api-svc6\AppIwcfg.exe"
  • In HKEY_CURRENT_USER\Software\AppDataLow\Software\Microsoft\(GUID)
    • Install = "{hex values}"
  • In HKEY_CURRENT_USER\Software\AppDataLow\Software\Microsoft\(GUID)
    • {GUID 2} = "{hex values}"
  • In HKEY_CURRENT_USER\Software\AppDataLow\Software\Microsoft\(GUID)
    • Client = "{hex values}"

Step 5

Search and delete this file

[ Learn More ]
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%\api-svc6\AppIwcfg.exe
  • %User Temp%\{random string}\{random string}.bat

Step 6

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