YARA · SEKOIA.IO Community
SEKOIA_Kimsuky_Konni_Dll
Rule based on structure offset and file extension
- Author
- Sekoia.io
- Date
- 2022-09-12
- Modified
- 2024-12-19
- Score / Quality
- 75 / 80
What this rule detects
Rule based on structure offset and file extension
Associated malware family: Kimsuky, Konni.
Targets: Windows PE.
It defines 14 patterns (5 text, 9 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
kimsuky-konni-dll.yarDetection Rule License 1.1
rule SEKOIA_Kimsuky_Konni_Dll : FILE
{
meta:
= "Rule based on structure offset and file extension"
= "Sekoia.io"
= "6a20c492-e932-41bd-ac4a-01d35bfb0c49"
= "2022-09-12"
= "2024-12-19"
= "https://github.com/SEKOIA-IO/Community"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/kimsuky_konni_dll.yar#L1-L29"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
= "7099156decdfe35cde22958133d851479f12180fff7b5744af0c549ab8259636"
= 75
= 80
= "FILE"
= "1.0"
= "TLP:CLEAR"
strings:
$ext_1 = ".zip" wide ascii fullword
$ext_2 = ".cab" wide ascii fullword
$ext_3 = ".rar" wide ascii fullword
$ext_4 = ".ini" wide ascii fullword
$ext_5 = ".dat" wide ascii fullword
$offset_structure_1 = { 8d ?? 08 02 00 00 }
$offset_structure_2 = { 8d ?? 10 04 00 00 }
$offset_structure_3 = { 8d ?? 18 06 00 00 }
$offset_structure_4 = { 8d ?? 20 08 00 00 }
$offset_structure_5 = { 8d ?? 28 0a 00 00 }
$offset_structure_6 = { 89 ?? f8 11 00 00 }
$offset_structure_7 = { 8d ?? fc 11 00 00 }
$offset_structure_8 = { 89 ?? 0c 12 00 00 }
$offset_structure_9 = { 89 ?? 10 12 00 00 }
condition:
uint16be( 0 ) == 0x4d5a and filesize < 11MB and all of them
}
Strings (14 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $ext_1 | text | ".zip" | wide ascii fullword |
| $ext_2 | text | ".cab" | wide ascii fullword |
| $ext_3 | text | ".rar" | wide ascii fullword |
| $ext_4 | text | ".ini" | wide ascii fullword |
| $ext_5 | text | ".dat" | wide ascii fullword |
| $offset_structure_1 | hex | { 8d ?? 08 02 00 00 } | |
| $offset_structure_2 | hex | { 8d ?? 10 04 00 00 } | |
| $offset_structure_3 | hex | { 8d ?? 18 06 00 00 } | |
| $offset_structure_4 | hex | { 8d ?? 20 08 00 00 } | |
| $offset_structure_5 | hex | { 8d ?? 28 0a 00 00 } | |
| $offset_structure_6 | hex | { 89 ?? f8 11 00 00 } | |
| $offset_structure_7 | hex | { 8d ?? fc 11 00 00 } | |
| $offset_structure_8 | hex | { 89 ?? 0c 12 00 00 } | |
| $offset_structure_9 | hex | { 89 ?? 10 12 00 00 } |
Condition
uint16be( 0 ) == 0x4d5a and filesize < 11MB and all of themIn plain words (Heuristic)
- The file must start with “MZ” — a Windows executable (PE).
- The file must be smaller than 11MB (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: 6a20c492-e932-41bd-ac4a-01d35bfb0c49
Metadata
| version | 1.0 |
|---|---|
| classification | TLP:CLEAR |
Tags:FILE
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