PE_EXPIRO.RAP

 Analysis by: Erika Bianca Mendoza
 Modified by: Jasen Sumalapao

 ALIASES:

Virus:Win32/Expiro.S (Microsoft), Virus.Win32.Expiro.w (Kaspersky), W32.Xpiro.D (Symantec), W32/Expiro.gen.h (NAI), W32/Expiro-H (Sophos), Win32.Expiro.W (FSecure), Virus.Win32.Expiro.i (v) (Sunbelt), W32/Expiro.E (Antivir), W32/Expiro.O (Authentium), Win32.Expiro.W (Bitdefender), W32.Expiro-15 (Clamav), W32/Expiro.W (Fortinet), W32/Expiro.O (Fprot), Virus.Win32.Expiro (Ikarus), a variant of Win32/Expiro.T virus (NOD32), W32/Expiro.gen (Panda), Virus.Win32.Expiro.SEP.4 (VBA32)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Infects files


This file infector appends its codes to target files. It infects certain file types by inserting code in the said files.

It modifies the Internet Explorer Zone Settings.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

30 Mar 2011

Arrival Details

This malware arrives via the following means:

  • may arrive in the system when infected files are executed
  • may be downloaded unknowingly when visiting malicious websites

Installation

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

  • kkq-vx_mtx1
  • kkq-vx_mtx{random number}
  • gazavat-svc
  • gazavat-svc_{random number}

Autostart Technique

This file infector drops the following files:

  • %Application Data%\{random}.dll - non-malicious

(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 and 7.)

File Infection

This file infector appends its codes to target files.

It infects files with the following file extensions by inserting code in the said files:

  • .EXE

Web Browser Home Page and Search Page Modification

This file infector modifies the Internet Explorer Zone Settings.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

7.940.16

FIRST VSAPI PATTERN DATE:

30 Mar 2011

VSAPI OPR PATTERN File:

7.941.00

VSAPI OPR PATTERN Date:

31 Mar 2011

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

Search and delete these files

[ 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%\{random}.dll

Step 3

Reset Internet security settings

[ Learn More ]

Step 4

Scan your computer with your Trend Micro product to clean files detected as PE_EXPIRO.RAP. 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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