Author: David John Agni   
 

Trojan-Ransom.Win32.Raas (Ikarus), Trojan-Ransom.Win32.Raas.a (Kaspersky),

 PLATFORM:

Windows

 OVER ALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE
Low
Medium
High
Critical

  • Threat Type:
    Trojan

  • Destructiveness:
    No

  • Encrypted:
    No

  • In the wild:
    Yes

  OVERVIEW

INFECTION CHANNEL: Dropped by other malware, Downloaded from the Internet

This is the Trend Micro detection for the Encryptor RaaS (Ransomware as a Service) that has the capability to set deadlines as well as for the ransom amount to increase. This new platform allows attackers and cybercriminals to create their own ransomware for free.

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

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

  TECHNICAL DETAILS

File size: 203264 bytes
File type: EXE
Memory resident: No
INITIAL SAMPLES RECEIVED DATE: 03 sierpnia 2015
PAYLOAD: Encrypts files, Steals information

Arrival Details

This Trojan 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 Trojan drops the following non-malicious files:

  • %Desktop%\encryptor_raas_readme_liesmich.txt - ransom notes

(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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.)

Information Theft

This Trojan gathers the following data:

  • Machine GUID

Other Details

This Trojan encrypts files with the following extensions:

  • 3dm
  • 3ds
  • 3g2
  • 3gp
  • 7z
  • abw
  • accdb
  • ai
  • aif
  • arc
  • as
  • asc
  • asf
  • ashdisc
  • asm
  • asp
  • aspx
  • asx
  • aup
  • avi
  • bbb
  • bdb
  • bibtex
  • bkf
  • bmp
  • bpn
  • btd
  • bz2
  • cdi
  • cer
  • cert
  • cfm
  • cgi
  • cpio
  • cpp
  • crt
  • csr
  • cue
  • c++
  • dds
  • dem
  • dmg
  • doc
  • docm
  • docx
  • dsb
  • dwg
  • dxf
  • eddx
  • edoc
  • eml
  • emlx
  • eps
  • epub
  • fdf
  • ffu
  • flv
  • gam
  • gcode
  • gho
  • gif
  • gpx
  • gz
  • hbk
  • hdd
  • hds
  • hpp
  • h++
  • ics
  • idml
  • iff
  • img
  • indd
  • ipd
  • iso
  • isz
  • iwa
  • j2k
  • jp2
  • jpf
  • jpeg
  • jpg
  • jpm
  • jpx
  • jsp
  • jspa
  • jspx
  • jst
  • key
  • keynote
  • kml
  • kmz
  • lic
  • lwp
  • lzma
  • m3u
  • m4a
  • m4v
  • max
  • mbox
  • md2
  • mdb
  • mdbackup
  • mddata
  • mdf
  • mdinfo
  • mds
  • mid
  • mov
  • mp3
  • mp4
  • mpa
  • mpb
  • mpeg
  • mpg
  • mpj
  • mpp
  • msg
  • mso
  • nba
  • nbf
  • nbi
  • nbu
  • nbz
  • nco
  • nes
  • note
  • nrg
  • nri
  • ods
  • odt
  • ogg
  • ova
  • ovf
  • oxps
  • p2i
  • p65
  • p7
  • pages
  • pct
  • pdf
  • pem
  • phtm
  • phtml
  • php
  • php3
  • php4
  • php5
  • phps
  • phpx
  • phpxx
  • pl
  • plist
  • pmd
  • pmx
  • png
  • ppdf
  • pps
  • ppsm
  • ppsx
  • ppt
  • pptm
  • pptx
  • ps
  • psd
  • pspimage
  • pst
  • pub
  • pvm
  • qcn
  • qcow
  • qcow2
  • qt
  • ra
  • rar
  • raw
  • rm
  • rtf
  • sbf
  • set
  • skb
  • slf
  • sme
  • smm
  • spb
  • sql
  • srt
  • ssc
  • ssi
  • stg
  • stl
  • svg
  • swf
  • sxw
  • syncdb
  • tar
  • tc
  • tex
  • tga
  • thm
  • tif
  • tiff
  • toast
  • torrent
  • tpl
  • ts
  • txt
  • vbk
  • vcard
  • vcd
  • vcf
  • vdi
  • vfs4
  • vhd
  • vhdx
  • vmdk
  • vob
  • wbverify
  • wav
  • webm
  • wmb
  • wpb
  • wps
  • xdw
  • xlr
  • xls
  • xlsx
  • xz
  • yuv
  • zip
  • zipx

NOTES:

It connects to the following website for instruction on how to recover the encrypted files:

  • https://{BLOCKED}toraveidf7.onion.to/vict?cust={value}&guid={GUID}

It searches the files it encrypts in the following drives:

  • Removable
  • Fixed
  • Network Drives

It avoids encrypting the following filenames:

  • encryptor_raas_readme_liesmich.txt
  • wallet.dat

It gives pressures to the victim by increasing the ransom payment price after the timeout.

  SOLUTION

Minimum scan engine: 9.750
VSAPI OPR PATTERN-VERSION: 11.833.00
VSAPI OPR PATTERN DATE: 05 sierpnia 2015

Step 1

Scan your computer with your Trend Micro product to delete files detected as RANSOM_CRYPRAAS.SM. 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.

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

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.


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