YARA · SEKOIA.IO Community
SEKOIA_Ransomware_Win_Karma
Detect the Karma ransomware payload
- Author
- Sekoia.io
- Date
- 2021-08-25
- Modified
- 2024-12-19
- Score / Quality
- 75 / 80
What this rule detects
Detect the Karma ransomware payload
Associated malware family: Karma.
Targets: Windows PE.
It defines 6 patterns (6 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
ransomware-win-karma.yarDetection Rule License 1.1
rule SEKOIA_Ransomware_Win_Karma : FILE
{
meta:
= "Detect the Karma ransomware payload"
= "Sekoia.io"
= "efd87a17-7c99-404a-8ea6-2f5c2121f9f2"
= "2021-08-25"
= "2024-12-19"
= "https://github.com/SEKOIA-IO/Community"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/ransomware_win_karma.yar#L1-L21"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
= "ef272be7ae5fea084120db95f7b002e9061d72442836e836ca43ddc7b461be4e"
= 75
= 80
= "FILE"
= "1.0"
= "TLP:CLEAR"
strings:
$a1 = "KARMA" ascii
$u1 = "KARMA" wide
$u2 = "-ENCRYPTED.txt" wide
$u3 = "Encrypting directory:" wide
$u4 = "Encrypting file:" wide
$u5 = "Trying to import ECC public key..." wide
condition:
uint16( 0 ) == 0x5A4D and filesize < 150KB and all of them
}
Strings (6 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $a1 | text | "KARMA" | ascii |
| $u1 | text | "KARMA" | wide |
| $u2 | text | "-ENCRYPTED.txt" | wide |
| $u3 | text | "Encrypting directory:" | wide |
| $u4 | text | "Encrypting file:" | wide |
| $u5 | text | "Trying to import ECC public key..." | wide |
Condition
uint16( 0 ) == 0x5A4D and filesize < 150KB and all of themIn plain words (Heuristic)
- The file must start with “MZ” — a Windows executable (PE).
- The file must be smaller than 150KB (a cheap guard that skips large files).
- All patterns in the rule must match.
Test this rule in your browser
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References
Licence & attribution
Author: Sekoia.io
Source repository: SEKOIA.IO Community @ a438a5901a
Licence: Detection Rule License 1.1 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: efd87a17-7c99-404a-8ea6-2f5c2121f9f2
Metadata
| version | 1.0 |
|---|---|
| classification | TLP:CLEAR |
Tags:FILE
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