TROJ_CRYPFUD.B

 Analysis by: Cris Nowell Pantanilla

 ALIASES:

Trojan-Spy.Win32.Zbot.sbpl (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan drops copies of itself in the Windows Common Startup folder to enable its automatic execution at every system startup.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

380,928 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

31 Mar 2015

Payload:

Encrypts files, Connects to URLs/IPs, Displays graphics/image

Installation

This Trojan drops the following files:

  • %Application Data%\fud.bmp
  • %Start Menu%\Programs\Startup\fud.bmp

(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.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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 Trojan drops copies of itself in the Windows Common Startup folder to enable its automatic execution at every system startup.

Other System Modifications

This Trojan sets the system's desktop wallpaper to the following image:

Other Details

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

  • http://{BLOCKED}is.info/open/script.php

It encrypts files with the following extensions:

  • 113
  • 1cd
  • 3gp
  • 73b
  • 7z
  • a3d
  • abf
  • abk
  • accdb
  • arj
  • as4
  • asm
  • asvx
  • ate
  • avi
  • bac
  • bak
  • bck
  • bkf
  • cdr
  • cer
  • cf
  • cpt
  • csv
  • db3
  • dbf
  • doc
  • docx
  • dt
  • dwg
  • erf
  • fbf
  • fbk
  • fbw
  • fbx
  • fdb
  • gbk
  • gho
  • gzip
  • iv2i
  • jpeg
  • jpg
  • key
  • keystore
  • ldf
  • m2v
  • m3d
  • max
  • mdb
  • mkv
  • mov
  • mpeg
  • nbd
  • nrw
  • nx1
  • odb
  • odc
  • odp
  • ods
  • odt
  • old
  • orf
  • p12
  • pdf
  • pef
  • ppsx
  • ppt
  • pptm
  • pptx
  • pst
  • ptx
  • pwm
  • pz3
  • qic
  • r3d
  • rar
  • raw
  • rtf
  • rwl
  • rx2
  • sbs
  • sldasm
  • sldprt
  • sn1
  • sna
  • spf
  • sr2
  • srf
  • srw
  • tbl
  • tib
  • tis
  • txt
  • wab
  • wps
  • x3f
  • xls
  • xlsb
  • xlsk
  • xlsm
  • xlsx
  • zip

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.572.06

FIRST VSAPI PATTERN DATE:

31 Mar 2015

VSAPI OPR PATTERN File:

11.573.00

VSAPI OPR PATTERN Date:

01 Apr 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

Identify and terminate files detected as TROJ_CRYPFUD.B

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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 4

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%\fud.bmp
  • %Start Menu%\Programs\Startup\fud.bmp

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_CRYPFUD.B. 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.