Analysis by: Nikko Tamana
 Modified by: Mio Fidel Villena
ALIASES:

TR/RedCap.yogmn (ANTIVIR), W32.Ramnit!dr (NORTON), Mal/Krypt12-A (SOPHOS_LITE)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • 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 uses a user interface (UI).

It drops files as ransom note.

  TECHNICAL DETAILS

File Size: 472,064 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 02 Nov 2017
Payload: Displays graphics/image, Displays windows, 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.

Other System Modifications

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

Other Details

This Ransomware uses the following user interface:

It does the following:

  • Can perform encryption routine on all different directories found at the same time
  • Exits and deletes itself only after performing all the encryption routines
  • Can hide itself
  • Execute the following commands usind CMD
    /C net view

Ransomware Routine

This Ransomware avoids encrypting files with the following strings in their file path:

  • .crypt12
  • .tmp
  • .sep
  • .tlb
  • .tbl
  • .tsp
  • .cmd
  • .ax
  • .olb
  • .com
  • .acm
  • .edb
  • .ini
  • .exe
  • .386
  • .73u
  • .8xu
  • .adm
  • .adml
  • .admx
  • .ani
  • .ann
  • .aos
  • .asec
  • .bio
  • .bk2
  • .blf
  • .bmk
  • .bud
  • .cab
  • .cdmp
  • .chs
  • .ci
  • .cnt
  • .cpi
  • .cpl
  • .cpq
  • .cur
  • .desklink
  • .deskthemepack
  • .dev
  • .diagcab
  • .diagcfg
  • .diagpkg
  • .dimax
  • .dit
  • .drv
  • .dss
  • .dyc
  • .ebd
  • .efi
  • .evtx
  • .ffa
  • .ffl
  • .ffo
  • .ffx
  • .ftg
  • .fts
  • .gmmp
  • .grl
  • .group
  • .grp
  • .h1s
  • .hdmp
  • .hhc
  • .hhk
  • .hiv
  • .hlp
  • .hpj
  • .hsh
  • .htt
  • .icl
  • .icns
  • .ico
  • .idi
  • .ifw
  • .ime
  • .img3
  • .inf_loc
  • .ins
  • .ion
  • .ipod
  • .itemdata-ms
  • .its
  • .jpn
  • .kbd
  • .key
  • .kor
  • .library-ms
  • .lnk
  • .log1
  • .log2
  • .lpd
  • .manifest
  • .mapimail
  • .mdmp
  • .mi4
  • .mlc
  • .mobileconfig
  • .msc
  • .msp
  • .msstyle
  • .msstyles
  • .mui
  • .mui_cccd5ae0
  • .mum
  • .mydocs
  • .nb0
  • .nbh
  • .nfo
  • .nls
  • .nt
  • .ntfs
  • .p7b
  • .pck
  • .pdr
  • .pfx
  • .pid
  • .pk2
  • .pol
  • .ppd
  • .prefpane
  • .prf
  • .printerexport
  • .ps2
  • .pwl
  • .rc1
  • .rc2
  • .rco
  • .reg
  • .regtrans-ms
  • .rfw
  • .rmt
  • .rs
  • .ruf
  • .savedsearch
  • .sbn
  • .scap
  • .scf
  • .scr
  • .shd
  • .shsh
  • .swp
  • .sys
  • .tdz
  • .tha
  • .theme
  • .trx_dll
  • .uce
  • .vga
  • .vgd
  • .vx_
  • .vxd
  • .webpnp
  • .wer
  • .wph
  • .wpx
  • .xfb
  • .xrm-ms
  • .dat
  • .db
  • .dll
  • .dmp
  • .ics
  • .mod
  • .mpa
  • .msu
  • .nomedia
  • .ocx
  • .ps1
  • .rom
  • .rtp
  • .shs
  • .spl
  • .themepack
  • .0
  • .000
  • .amlv
  • .automaticdestinations-ms
  • .bashrc
  • .bash_history
  • .bash_profile
  • .bin
  • .bk1
  • .bom
  • .c32
  • .cat
  • .cgz
  • .chg
  • .chk
  • .cht
  • .clb
  • .cpr
  • .crash
  • .dlx
  • .dvd
  • .edj
  • .elf
  • .emerald
  • .etl
  • .evt
  • .fid
  • .fpbf
  • .help
  • .idx
  • .ius
  • .job
  • .lfs
  • .lockfile
  • .lst
  • .mbr
  • .mem
  • .metadata_never_index
  • .panic
  • .pat
  • .pit
  • .pnf
  • .ppm
  • .profile
  • .prt
  • .qvm
  • .saver
  • .sbf
  • .schemas
  • .sdb
  • .searchconnector-ms
  • .sfcache
  • .so.0
  • .sqm
  • .str
  • .wdf
  • .wdgt
  • .wgz
  • .zone.identifier

It avoids encrypting files found in the following folders:

  • D:\owncloud
  • D:\gdrive

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

  • ={Random 5 Digit Number}=hernansec@{BLOCKED}mail.ch.crypt12

It drops the following file(s) as ransom note:

  • {Folder Path of Encrypted Files}\!!!!readme!!!.txt

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.756.08
FIRST VSAPI PATTERN DATE: 02 Nov 2017
VSAPI OPR PATTERN File: 13.757.00
VSAPI OPR PATTERN Date: 03 Nov 2017

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

Terminate a malware/grayware process

[ Learn More ]

*Note: If the detected process is not displayed in theWindows Task Manager, continue doing the next steps.

    DATA_GENERIC
  • Select the process then press the End Process button.
  • To check if the malware/grayware process/es has/have been terminated, close Windows Task Manager then open it again.
  • Close Windows Task Manager.

    • Step 4

    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.  
    • {Folder Path of Encrypted Files}\!!!!readme!!!.txt

    Step 5

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

    Step 6

    Restore encrypted files from backup.


    Did this description help? Tell us how we did.