Ransom.Win64.AKIRA.THDBFBD

September 14, 2023
 Analysis by: John Rainier Navato
 ALIASES:

Generic.Ransom.Akira.A.BEDB27F1 (BITDEFENDER)

 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:

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 encrypts files with specific file extensions. 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"

Information Theft

This Ransomware accepts the following parameters:

  • -p, --encryption_path → used for specifying the directory to be encrypted.
  • -l → used for displaying a list of logical drives mounted in the system
  • -s, --share_files → used for encrypting shared folders
  • -n, --encryption_percent → enables the user to specify the percentage of data in each file that should be encrypted. The default setting is 50.
  • -remote -> used for preventing the Windows restart manager from being triggered if the ransomware fails to open files, assuming these files are located on a remote host such as a shared folder. This is used in conjunction with the “--share_files” parameter.

Other Details

This Ransomware 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.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

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

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

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

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

  • .akira

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

  • {Encrypted Directory}\akira_readme.txt

It avoids encrypting files with the following file extensions:

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

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.692.03

FIRST VSAPI PATTERN DATE:

12 Sep 2023

VSAPI OPR PATTERN File:

18.693.00

VSAPI OPR PATTERN Date:

13 Sep 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.  
  • {Encrypted Directory}\akira_readme.txt

Step 5

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