RANSOM_HOTDEM.A

 Analysis by: Marvelous Pelin

 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

Infection Channel:

Dropped by other malware, Downloaded from the Internet


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:

178,176 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

07 Nov 2016

Payload:

Encrypts files, renames files, Drops files, Connects to URLs/IPs

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 files:

  • {folders containing encrypted files}\README_PLEASE.txt - ransom note

Backdoor Routine

This Trojan connects to the following URL(s) to send and receive commands from a remote malicious user:

  • http://{BLOCKED}.{BLOCKED}.41.76/g.php?

Other Details

This Trojan encrypts files with the following extensions:

  • .1cd
  • .3d
  • .3d4
  • .3df8
  • .3fr
  • .3g2
  • .3gp
  • .3gp2
  • .3mm
  • .7z
  • .aac
  • .abk
  • .abw
  • .ac3
  • .accdb
  • .ace
  • .act
  • .ade
  • .adi
  • .adpb
  • .adr
  • .adt
  • .ai
  • .aim
  • .aip
  • .ais
  • .amf
  • .amr
  • .amu
  • .amx
  • .amxx
  • .ans
  • .ap
  • .ape
  • .api
  • .arc
  • .ari
  • .arj
  • .aro
  • .arr
  • .arw
  • .asa
  • .asc
  • .ascx
  • .ase
  • .asf
  • .ashx
  • .asmx
  • .asp
  • .asr
  • .avi
  • .avs
  • .bak
  • .bay
  • .bck
  • .bdp
  • .bdr
  • .bib
  • .bic
  • .big
  • .bik
  • .bkf
  • .blp
  • .bmc
  • .bmf
  • .bml
  • .bmp
  • .boc
  • .bp2
  • .bp3
  • .bpl
  • .bsp
  • .cag
  • .cam
  • .cap
  • .car
  • .cbr
  • .cbz
  • .cc
  • .ccd
  • .cch
  • .cd
  • .cdr
  • .cer
  • .cfg
  • .cgf
  • .chk
  • .clr
  • .cms
  • .cod
  • .col
  • .cp
  • .cpp
  • .cr2
  • .crd
  • .crt
  • .crw
  • .cs
  • .csi
  • .cso
  • .ctt
  • .cty
  • .cwf
  • .dal
  • .dap
  • .dbb
  • .dbf
  • .dbx
  • .dcp
  • .dcr
  • .dcu
  • .ddc
  • .ddcx
  • .dem
  • .der
  • .dev
  • .dex
  • .dic
  • .dif
  • .dii
  • .dir
  • .disk
  • .divx
  • .diz
  • .djvu
  • .dmg
  • .dng
  • .dob
  • .doc
  • .docm
  • .docx
  • .dot
  • .dotm
  • .dotx
  • .dox
  • .dpk
  • .dpl
  • .dpr
  • .dsk
  • .dsp
  • .dvd
  • .dvi
  • .dvx
  • .dwg
  • .dxe
  • .dxf
  • .dxg
  • .elf
  • .eps
  • .eql
  • .erf
  • .err
  • .euc
  • .evo
  • .ex
  • .exif
  • .f90
  • .faq
  • .fcd
  • .fdr
  • .fds
  • .ff
  • .fla
  • .flp
  • .flv
  • .for
  • .fpp
  • .gam
  • .gif
  • .grf
  • .gthr
  • .gz
  • .gzig
  • .h3m
  • .h4r
  • .htm
  • .html
  • .idx
  • .img
  • .indd
  • .ink
  • .ipa
  • .isu
  • .isz
  • .itdb
  • .itl
  • .iwd
  • .jar
  • .jav
  • .java
  • .jc
  • .jfif
  • .jgz
  • .jif
  • .jiff
  • .jpc
  • .jpeg
  • .jpf
  • .jpg
  • .jpw
  • .js
  • .kdc
  • .kmz
  • .kwd
  • .lbi
  • .lcd
  • .lcf
  • .ldb
  • .lgp
  • .log
  • .lp2
  • .ltm
  • .ltr
  • .lvl
  • .mag
  • .man
  • .map
  • .max
  • .mbox
  • .mbx
  • .mcd
  • .md3
  • .mdb
  • .mdf
  • .mdl
  • .mdn
  • .mds
  • .mef
  • .mic
  • .mip
  • .mlx
  • .mod
  • .moz
  • .mp3
  • .mp4
  • .mpeg
  • .mpg
  • .mrw
  • .msg
  • .msp
  • .mxp
  • .nav
  • .ncd
  • .nds
  • .nef
  • .nfo
  • .now
  • .nrg
  • .nri
  • .nrw
  • .odb
  • .odc
  • .odf
  • .odi
  • .odm
  • .odp
  • .ods
  • .odt
  • .oft
  • .oga
  • .ogg
  • .opf
  • .orf
  • .owl
  • .oxt
  • .p12
  • .p7b
  • .p7c
  • .pab
  • .pak
  • .pbf
  • .pbp
  • .pbs
  • .pcv
  • .pdd
  • .pdf
  • .pef
  • .pem
  • .pfx
  • .php
  • .pkb
  • .pkh
  • .pl
  • .plc
  • .pli
  • .pm
  • .png
  • .pot
  • .potm
  • .potx
  • .ppd
  • .ppf
  • .pps
  • .ppsm
  • .ppsx
  • .ppt
  • .pptm
  • .pptx
  • .prc
  • .prt
  • .psa
  • .psd
  • .pst
  • .ptx
  • .puz
  • .pwf
  • .pwi
  • .pxp
  • .qbb
  • .qdf
  • .qel
  • .qif
  • .qpx
  • .qtq
  • .qtr
  • .r3d
  • .ra
  • .raf
  • .rar
  • .raw
  • .res
  • .rev
  • .rgn
  • .rng
  • .rrt
  • .rsrc
  • .rsw
  • .rte
  • .rtf
  • .rts
  • .rtx
  • .rum
  • .run
  • .rv
  • .rw2
  • .rwl
  • .sad
  • .saf
  • .sav
  • .scm
  • .scn
  • .scx
  • .sdb
  • .sdc
  • .sdn
  • .sds
  • .sdt
  • .sen
  • .sfs
  • .sfx
  • .sh
  • .shar
  • .shr
  • .shw
  • .slt
  • .snp
  • .so
  • .spr
  • .sql
  • .sqx
  • .sr2
  • .srf
  • .srt
  • .srw
  • .ssa
  • .std
  • .stt
  • .stx
  • .sud
  • .svi
  • .svr
  • .swd
  • .swf
  • .tar
  • .tax2013
  • .tax2014
  • .tbz2
  • .tch
  • .tcx
  • .text
  • .tg
  • .thmx
  • .tif
  • .tlz
  • .tpu
  • .tpx
  • .trp
  • .tu
  • .tur
  • .txd
  • .txf
  • .txt
  • .uax
  • .udf
  • .umx
  • .unr
  • .unx
  • .uop
  • .upoi
  • .url
  • .usa
  • .usx
  • .ut2
  • .ut3
  • .utc
  • .utx
  • .uvx
  • .uxx
  • .val
  • .vc
  • .vcd
  • .vdo
  • .ver
  • .vhd
  • .vmf
  • .vmt
  • .vsi
  • .vtf
  • .w3g
  • .w3x
  • .wad
  • .war
  • .wav
  • .wave
  • .waw
  • .wb2
  • .wbk
  • .wdgt
  • .wks
  • .wm
  • .wma
  • .wmd
  • .wmdb
  • .wmmp
  • .wmv
  • .wmx
  • .wow
  • .wpd
  • .wpk
  • .wpl
  • .wps
  • .wsh
  • .wtd
  • .wtf
  • .wvx
  • .x3f
  • .xl
  • .xla
  • .xlam
  • .xlc
  • .xlk
  • .xll
  • .xlm
  • .xlr
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xltx
  • .xlv
  • .xlwx
  • .xpi
  • .xpt
  • .xvid
  • .xwd
  • .yab
  • .yps
  • .z02
  • .z04
  • .zap
  • .zip
  • .zipx
  • .zoo

It renames encrypted files using the following names:

  • {original filename and extension}.lrmethod

It does the following:

  • It prevents encrypting files in the following directories:
    • \Documents and Settings\NetworkService\
    • \Documents and Settings\LocalService\
    • \Documents and Settings\Default User\
    • \Documents and Settings\All Users\
    • \Local Settings\
    • \Recycler\
    • \AppData\Roaming\
    • \AppData\LocalLow\
    • \AppData\Local\
    • \Drivers\
    • \Recovery\
    • \System Volume Information\
    • \ProgramData\
    • \Users\All Users\
    • \$Recycle.Bin\
    • \Boot\
    • \Windows\

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.906.09

FIRST VSAPI PATTERN DATE:

19 Nov 2016

VSAPI OPR PATTERN File:

12.907.00

VSAPI OPR PATTERN Date:

20 Nov 2016

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

Restart in Safe Mode

[ Learn More ]

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.  
  • {folders containing encrypted files}\README_PLEASE.txt

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_HOTDEM.A. 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 6

Restore encrypted files from backup.


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