YARA · SEKOIA.IO Community
SEKOIA_Infostealer_Win_Nosu
Finds Nosu samples based on characteristic strings
- Author
- Sekoia.io
- Date
- 2022-12-15
- Modified
- 2024-12-19
- Score / Quality
- 75 / 80
What this rule detects
Finds Nosu samples based on characteristic strings
Associated malware family: Nosu.
Targets: Windows PE.
It defines 3 patterns (3 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
infostealer-win-nosu.yarDetection Rule License 1.1
rule SEKOIA_Infostealer_Win_Nosu : FILE
{
meta:
= "Finds Nosu samples based on characteristic strings"
= "Sekoia.io"
= "9823af25-e30b-4514-a59c-02dd19fe368d"
= "2022-12-15"
= "2024-12-19"
= "https://github.com/SEKOIA-IO/Community"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/infostealer_win_nosu.yar#L1-L17"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
= "f18db2008aa9175fc423133fd6d5872c5750d011aad73c373505347443d5032c"
= 75
= 80
= "FILE"
= "1.0"
= "TLP:CLEAR"
strings:
$str0 = "C:\\xampp\\htdocs\\nosu\\core\\release\\lilly.pdb" ascii
$str1 = "{\"gp\":\"%s\",\"app\":\"%S\"," ascii
$str2 = "stored in zip:\\%s" wide
condition:
uint16( 0 ) == 0x5A4D and 1 of them and filesize < 1MB
}
Strings (3 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $str0 | text | "C:\\xampp\\htdocs\\nosu\\core\\release\\lilly.pdb" | ascii |
| $str1 | text | "{\"gp\":\"%s\",\"app\":\"%S\"," | ascii |
| $str2 | text | "stored in zip:\\%s" | wide |
Condition
uint16( 0 ) == 0x5A4D and 1 of them and filesize < 1MBIn plain words (Heuristic)
- The file must start with “MZ” — a Windows executable (PE).
- The file must be smaller than 1MB (a cheap guard that skips large files).
- At least 1 patterns in the rule must match.
Test this rule in your browser
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Drop a file here or click to chooseScanned locally with YARA-X. Files up to 200 MB.
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: 9823af25-e30b-4514-a59c-02dd19fe368d
Metadata
| version | 1.0 |
|---|---|
| classification | TLP:CLEAR |
Tags:FILE
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