Analysis by: John Rainier Navato
ALIASES:

Ransom:Win64/Akira.AA!MTB (MICROSOFT)

 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 does not have any propagation routine.

It does not have any backdoor routine.

It does not have any information-stealing capability.

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: 1,029,120 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 06 Feb 2024
Payload: Encrypts files, Drops 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 drops the following files:

  • {Malware File Path}\Log-{Date of execution in MM-DD-YYYY-hh-mm-ss}.txt → malware logs
  • {Encrypted File Path}\{Random}.arika → deleted afterwards

It adds the following processes:

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

Propagation

This Ransomware does not have any propagation routine.

Backdoor Routine

This Ransomware does not have any backdoor routine.

Rootkit Capabilities

This Ransomware does not have rootkit capabilities.

Information Theft

This Ransomware accepts the following parameters:

  • -p, --encryption_path → used to specify a directory to be encrypted
  • -l → used to list the logical drives mounted in the system in the malware logs
  • -s, --share_files → used to specify shared folder to be encrypted
  • -n, --encryption_percent → enables the user to specify the percentage of data in each file that should be encrypted.
  • -localonly → used to only encrypt the affected system

It does not have any information-stealing capability.

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.

It does not exploit any vulnerability.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • Full encryption:
    • .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
    • .fdb
    • .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
    • .temx
    • .tmd
    • .tps
    • .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
  • Partial encryption:
    • files with other extensions

It avoids encrypting files found in the following folders:

  • $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 File Path}\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: 19.148.02
FIRST VSAPI PATTERN DATE: 09 Feb 2024
VSAPI OPR PATTERN File: 19.149.00
VSAPI OPR PATTERN Date: 10 Feb 2024

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.XXPE50FFF077

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 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.
  • {Malware File Path}\Log-{Date of infection in MM-DD-YYYY-hh-mm-ss}.txt
  • {Encrypted File Path}\{Random}.arika
  • {Encrypted File Path}\akira_readme.txt

Step 5

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