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Ransom.Win64.AKIRA.THDBFBC

August 29, 2023
 Analysis by: Neljorn Nathaniel Aguas
 ALIASES:

Ransom:Win64/Akira!MTB (MICROSOFT)

 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:

Downloaded from the Internet, Dropped by other malware

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 drops files as ransom note. It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

File Size:

586,240 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

25 Apr 2023

Payload:

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 processes:

  • powershell.exe -Command "Get-WmiObject Win32_Shadowcopy | Remove-WmiObject"

Other Details

This Ransomware encrypts files with the following extensions:

  • .4dd
  • .accdb
  • .4dl
  • .accde
  • .accdc
  • .accdt
  • .accdr
  • .adb
  • .accft
  • .adf
  • .ade
  • .arc
  • .adp
  • .alf
  • .ora
  • .btr
  • .ask
  • .cat
  • .bdf
  • .ckp
  • .cdb
  • .cpd
  • .cma
  • .dad
  • .dacpac
  • .daschema
  • .dadiagrams
  • .db-shm
  • .db
  • .db3
  • .db-wal
  • .dbf
  • .dbc
  • .dbt
  • .dbs
  • .dbx
  • .dbv
  • .dct
  • .dcb
  • .ddl
  • .dcx
  • .dp1
  • .dlis
  • .dsk
  • .dqy
  • .dtsx
  • .dsn
  • .eco
  • .dxl
  • .edb
  • .ecx
  • .exb
  • .epim
  • .fdb
  • .fcd
  • .fmp
  • .fic
  • .fmpsl
  • .fmp12
  • .fp3
  • .fol
  • .fp5
  • .fp4
  • .fpt
  • .fp7
  • .gdb
  • .frm
  • .gwi
  • .grdb
  • .his
  • .hdb
  • .idb
  • .ib
  • .itdb
  • .ihx
  • .jet
  • .itw
  • .kdb
  • .jtx
  • .kexic
  • .kexi
  • .lgc
  • .kexis
  • .maf
  • .lwx
  • .mar
  • .maq
  • .mav
  • .mas
  • .mdf
  • .mdb
  • .mrg
  • .mpd
  • .mwb
  • .mud
  • .ndf
  • .myd
  • .nrmlib
  • .nnt
  • .ns3
  • .ns2
  • .nsf
  • .ns4
  • .nv2
  • .nv
  • .nyf
  • .nwdb
  • .oqy
  • .odb
  • .owc
  • .orx
  • .p97
  • .p96
  • .pdb
  • .pan
  • .pnz
  • .pdm
  • .qvd
  • .qry
  • .rctd
  • .rbf
  • .rodx
  • .rod
  • .rsd
  • .rpd
  • .sbf
  • .sas7bdat
  • .sdb
  • .scx
  • .sdf
  • .sdc
  • .spq
  • .sis
  • .sqlite
  • .sql
  • .sqlitedb
  • .sqlite3
  • .temx
  • .te
  • .tps
  • .tmd
  • .trm
  • .trc
  • .udl
  • .udb
  • .v12
  • .usr
  • .vpd
  • .vis
  • .wdb
  • .vvv
  • .wrk
  • .wmdb
  • .xld
  • .xdb
  • .abcddb
  • .xmlff
  • .abx
  • .abs
  • .adn
  • .accdw
  • .fm5
  • .db2
  • .icg
  • .hjt
  • .kdb
  • .icr
  • .maw
  • .lut
  • .mdt
  • .mdn
  • .vhd
  • .vdi
  • .pvm
  • .vmdk
  • .vmsn
  • .vmem
  • .nvram
  • .vmsd
  • .raw
  • .vmx
  • .subvol
  • .qcow2
  • .vsv
  • .bin
  • .vmrs
  • .avhd
  • .avdx
  • .vhdx
  • .iso
  • .vmcx

It does the following:

  • It uses the Windows Restart Manager API to close processes or shut down Windows services that may be keeping a file open and preventing encryption.

It accepts the following parameters:

  • -p → Path to only encrypt files
  • -s → Path to a file containing list of shares to include in the encryption
  • -n → Encryption percentage on how much content of the files will be encrypted
  • -l → Enable to display log

Ransomware Routine

This Ransomware avoids encrypting files found in the following folders:

  • winnt
  • tmp
  • temp
  • thumb
  • $Recycle.Bin
  • $RECYCLE.BIN
  • System Volume Information
  • Boot
  • Windows
  • Trend Micro
  • ProgramData

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

  • .akira

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

  • {Directories Containing Encrypted Files}\akira_readme.txt

It avoids encrypting files with the following file extensions:

  • .exe
  • .dll
  • .lnk
  • .sys
  • .msi
  • .akira

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.408.02

FIRST VSAPI PATTERN DATE:

26 Apr 2023

VSAPI OPR PATTERN File:

18.409.00

VSAPI OPR PATTERN Date:

27 Apr 2023

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    • TROJ.Win32.TRX.XXPE50FFF071

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

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.
  • {Directories Containing Encrypted Files}\akira_readme.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win64.AKIRA.THDBFBC. 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.


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