Analysis by: Noel Anthony Llimos

ALIASES:

Trojan-Ransom.Win32.Cryptor.brd (KASPERSKY), Ransom.GandCrab (Norton), Troj/Rusenger-A (Sophos_LITE)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

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

It encrypts files with specific file extensions.

  TECHNICAL DETAILS

File Size: 1,182,720 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 19 Feb 2018
Payload: Displays message/message boxes, Encrypts files

Arrival Details

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

  • 2111143252160967372

Other Details

This Ransomware does the following:

  • It encrypts files in all fixed, removable, and network drives and shares.
  • It drops a ransom note in every directory that the malware had successfully encrypted.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .zip
  • .rar
  • .7z
  • .tar
  • .gzip
  • .gz
  • .tgz
  • .arj
  • .jpg
  • .jpeg
  • .psd
  • .cdr
  • .dwg
  • .max
  • .bmp
  • .gif
  • .png
  • .doc
  • .docx
  • .xls
  • .xlsx
  • .ppt
  • .pptx
  • .rtf
  • .pdf
  • .djvu
  • .htm
  • .html
  • .efd
  • .txt
  • .mdb
  • .cer
  • .p12
  • .pfx
  • .kwm
  • .pwm
  • .md
  • .mdf
  • .iso
  • .tib
  • .nrg
  • .gho
  • .ghost
  • .ghs
  • .bak
  • .bkp
  • .bkf
  • .1cd
  • .2cd
  • .1cd2
  • .dbf
  • .dd
  • .ert
  • .cf
  • .cfu
  • .erf
  • .epf
  • .dt
  • .cdx
  • .pfl
  • .lst
  • .gdb
  • .gbk
  • .fdb
  • .fbk
  • .ldf
  • .sql
  • .odt
  • .rn
  • .ifo
  • .lnk
  • .cbu
  • .mov
  • .m2v
  • .dbx
  • .bln
  • .dic
  • .tpl
  • .a2u
  • .mcx
  • .key
  • .mkd
  • .bkc
  • .wav
  • .tbh
  • .tbc
  • .tbb
  • .tbn
  • .rst
  • .sel
  • .pas
  • .ib
  • .zrb
  • .eif
  • .pgd
  • .trn
  • .nbi
  • .res
  • .hbk
  • .eps
  • .indd
  • .ods
  • .ppd
  • .pln
  • .plan
  • .bpn
  • .blf
  • .ldw
  • .box
  • .frw
  • .pst
  • .mxl
  • .xml
  • .idf
  • .war
  • .tab
  • .nbr
  • .hdf
  • .rcf
  • .lgp
  • .lgf
  • .elf
  • .pgp
  • .frf
  • .vhd
  • .frp
  • .gsh
  • .eet
  • .gdoc
  • .hbi
  • .svc
  • .dmp
  • .accdb
  • .csv
  • .arc
  • .mb
  • .px
  • .xg0
  • .yg0
  • .db.
  • .abd
  • .flx
  • .srx
  • .tbi
  • .his
  • .dfp
  • .packed
  • .backup
  • .map
  • .vmem
  • .vmdk
  • .zsp
  • .bpl
  • .1cl
  • .bac
  • .tbk
  • .lzh
  • .udb
  • .7zip
  • .mxlz
  • .bls
  • .rbf
  • .bdf
  • .bde
  • .vbe
  • .vbk
  • .dbk
  • .bks
  • .frm
  • .myd
  • .myi
  • .php
  • .vrd
  • .nbk
  • .bip
  • .qib
  • .cbf
  • .info
  • .export
  • .wbverify
  • .wbcat
  • .cdb
  • .ima
  • .imh
  • .vbx
  • .jbc
  • .sqm
  • .cfl
  • .tmp
  • .mig
  • .apc
  • .vhdx
  • .ldb
  • .lgd
  • .edb
  • .vsv
  • .avhd
  • .wim
  • .cuc
  • .mft
  • .tbl
  • .adb
  • .car
  • .ver
  • .nvram
  • .vmx
  • .vmxf
  • .vmss
  • .tmf
  • .dump
  • .eml
  • .msf
  • .ndf
  • .dcm
  • .stm
  • .vdi
  • .bz2
  • .xlsb
  • .old
  • .pf
  • .pml
  • .idx
  • .lbl
  • .lvd
  • .prv
  • .tmp0
  • .pak
  • .local
  • .rec
  • .ifs
  • .xsd
  • .dpr
  • .dproj
  • .dcu
  • .fpf
  • .ps1
  • .saved
  • .save
  • .cpr
  • .bf
  • .bf3
  • .rep
  • .apk
  • .sct
  • .fxp
  • .vct
  • .fpt
  • .prg
  • .vcx
  • .xxx
  • .ora
  • .sfpe
  • .svp
  • .ogd
  • .rdf
  • .frx
  • .dot
  • .rpt
  • .pm
  • .pl
  • .ctl
  • .gbp
  • .sfpz
  • .scn
  • .ord
  • .fil
  • .ect
  • .ava
  • .1ey
  • .mde
  • .wnw
  • .vvr
  • .dfb
  • .dff
  • .rsu
  • .gsn
  • .pdt
  • .vdb
  • .ddt
  • .6tr
  • .pkg
  • .trc
  • .lg
  • .ddf
  • .str
  • .9tr
  • .8tr
  • .8t0
  • .upd
  • .ndt
  • .pbf
  • .one
  • .onetoc2
  • .rpb
  • .dg
  • .dat
  • .fkc
  • .dbt
  • .eso
  • .esl
  • .mac
  • .sgn
  • .pbd
  • .sst
  • .shd
  • .bco
  • .vib
  • .vbm
  • .prb
  • .als
  • .sqx
  • .nag
  • .vpc
  • .pkr
  • .skr
  • .mdx
  • .prk
  • .rvs
  • .iv2i
  • .sv2i
  • .v2i
  • .gfo
  • .gfr
  • .gfd
  • .tst
  • .sdf
  • .qst
  • .nef
  • .gpd
  • .dsus
  • .psl
  • .pfm
  • .xsc
  • .xstk
  • .oxps
  • .qrp
  • .xlsm
  • .ai
  • .grd
  • .bcp
  • .mod
  • .mdmp
  • .esbak
  • .mbox
  • .shs
  • .viprof
  • .sbk
  • .dis
  • .dcf
  • .xch
  • .utf
  • .sbp
  • .sqlite
  • .ost
  • .vmp
  • .arch
  • .ans
  • .twd
  • .cbm
  • .rez
  • .mdt
  • .mdw
  • .blk
  • .vmsn
  • .vmsd
  • .vmpl
  • .kdc
  • .sob
  • .sobx
  • .sac
  • .sacx
  • .smf
  • .smfx
  • .ssd
  • .sln
  • .tdb
  • .dbs
  • .diff
  • .plb
  • .vswp
  • .q1c
  • .out
  • .scx
  • .tnx
  • .klt
  • .~klt~2
  • .nsf
  • .adi
  • .md5
  • .gd
  • .ctlg
  • .sdl
  • .lky
  • .burn
  • .sem
  • .hive
  • .ntx
  • .bz
  • .fld
  • .imm
  • .vrfs
  • .ldif
  • .req
  • .pwd
  • .meb
  • .laccdb
  • .kmn
  • .pka
  • .img
  • .fbf
  • .nc
  • .bck
  • .ssf
  • .jrs
  • .drs
  • .dtz
  • .fob
  • .pfi
  • .wrk
  • .vsd
  • .sbin
  • .last
  • .atc
  • .atg
  • .py
  • .~ini
  • .shdb
  • .shdl
  • .sdb
  • .new
  • .rk6
  • .mak
  • .v8i
  • .1txt
  • .mtl
  • .pro
  • .file
  • .amr
  • .ppsx
  • .irsi
  • .irsf
  • .irss
  • .fi
  • .snp
  • .pck
  • .ips
  • .xz
  • .tps
  • .avhdx
  • .vmcx
  • .vmrs
  • .awr
  • .unf
  • .ok
  • .okk
  • .lic
  • .lis
  • .dz
  • .vvv
  • .apx
  • .cmt
  • .obf
  • .afd
  • .pnl
  • .nif
  • .cnc
  • .lay6
  • .tid
  • .a3d
  • .custom
  • .cui
  • .cuix
  • .vlx
  • .lsp
  • .dcl
  • .mnc
  • .mns
  • .mnr
  • .lrv
  • .thm
  • .ssp
  • .spr
  • .ovf
  • .repx
  • .keg
  • .ifm
  • .efm
  • .btr
  • .sna
  • .blb
  • .amp
  • .rgt
  • .bg
  • .dafile
  • .arh
  • .cr2
  • .$$$
  • .[0-9]+
  • .n[0-9]
  • .nd[0-9]
  • .6t[0-9]
  • .st[0-9]
  • .fdb[0-9]
  • .db[0-9]
  • .dt[0-9]
  • .nx[0-9]
  • .gopaymeb
  • .stop
  • .lock
  • .granit
  • .ua_
  • .enc
  • .crypt
  • .cripted
  • .criptfiles
  • .wallet
  • .vault
  • .en

It appends the following extension to the file name of the encrypted files:

  • .messenger-{random letters and numbers}

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.978.01
FIRST VSAPI PATTERN DATE: 19 Feb 2018
VSAPI OPR PATTERN File: 13.979.00
VSAPI OPR PATTERN Date: 20 Feb 2018

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

Identify and terminate files detected as RANSOM_RUSSENGER.THBBOAH

[ 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 4

Scan your computer with your Trend Micro product to delete files detected as RANSOM_RUSSENGER.THBBOAH. 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 the following Trend Micro Support pages for more information:

Step 5

Restore encrypted files from backup.


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