arrow_back
search
close

PE_QUERVAR.E-O

September 28, 2012
 Analysis by: Christopher Daniel So
 ALIASES:

Trojan.Win32.Rimecud.d (v) (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware, Infects files


This malware downloads a ransomware that pretends to enforce copyright laws and locks the affected system, preventing users from using it.

To get a one-glance comprehensive view of the behavior of this File infector, refer to the Threat Diagram shown below.

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

It injects its dropped file/component to specific processes.

It creates an infection marker in infected files.

  TECHNICAL DETAILS

File Size:

332,800 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

27 Sep 2012

Payload:

Connects to URLs/IPs, Downloads files

Arrival Details

This file infector 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 file infector drops the following copies of itself into the affected system:

  • %User Profile%\Application Data\{random folder name}\{random file name}.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It drops the following component file(s):

  • %User Profile%\Application Data\{random folder name}\{random file name}.exe.lnk
  • %User Profile%\Application Data\{random folder name}\{random file name}.exe.ini

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It creates the following folders:

  • %User Profile%\Application Data\{random folder name}

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It injects its dropped file/component to the following processes:

  • csrss.exe

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

It terminates itself if it finds the following processes in the affected system's memory:

  • taskmgr.exe

Autostart Technique

This file infector modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
load = "%User Profile%\Application Data\{random folder name}\{random filename}.exe.lnk"

(Note: The default value data of the said registry entry is "".)

File Infection

This file infector infects the following file types:

  • exe
  • doc
  • docx
  • xls
  • xlsx

It creates an infection marker in infected files.

Download Routine

This file infector connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}l.ru/33797470/2a06754.50664748/3052832ace10d474336096b36fbd49f05f190.exe?{random characters} - detected by Trend Micro as TROJ_SIREFEF.SZP
  • http://{BLOCKED}0.com/c/osnovnoj2.exe?{random number} - detected by Trend Micro as TROJ_RANSOM.CMY

Other Details

This file infector connects to the following possibly malicious URL:

  • http://{BLOCKED}ewidea1.ru/1.php?{random characters}&pin={random characters}&crc={random characters}
  • http://www. {BLOCKED}oservisi.com/test/php/way.php?{random characters}&pin=58252D00982BC1DA&crc={random characters}

NOTES:
This file infector rename the extension of the infected file as follows:

  • .doc to .cod.scr
  • .docx to .xcod.scr
  • .xls to .slx.scr
  • .xlsx to .xslx.scr

It then deletes the original copy of the infected files.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.428.01

FIRST VSAPI PATTERN DATE:

28 Sep 2012

VSAPI OPR PATTERN File:

9.429.00

VSAPI OPR PATTERN Date:

28 Sep 2012

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

Remove malware/grayware files dropped/downloaded by PE_QUERVAR.E-O

Step 3

Scan your computer with your Trend Micro product and note files detected as PE_QUERVAR.E-O

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

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.
  • %User Profile%\Application Data\{random folder name}

Step 6

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • From: load = "%User Profile%\Application Data\{random folder name}\{random filename}.exe.lnk"
      To: load = ""

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as PE_QUERVAR.E-O. 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.


Did this description help? Tell us how we did.

Related Web Attack