YARA · WithSecure Labs IOCs
WITHSECURELABS_GREYVIBE_JSLOADER_2
Detects common strings found across one of GREYVIBE's loaders (observed in PhantomMail campaign)
- Author
- WithSecure
- Date
- 2026-05-28
- Score / Quality
- 75 / 75
What this rule detects
Detects common strings found across one of GREYVIBE's loaders (observed in PhantomMail campaign)
It defines 4 patterns (4 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
greyvibe-jsloader-2.yarBSD 2-Clause License
rule WITHSECURELABS_GREYVIBE_JSLOADER_2
{
meta:
= "Detects common strings found across one of GREYVIBE's loaders (observed in PhantomMail campaign)"
= "WithSecure"
= "9901d2df-6539-51c6-a24d-c06a7e898a6a"
= "2026-05-28"
= "2026-05-28"
= "https://github.com/WithSecureLabs/iocs"
= "https://github.com/WithSecureLabs/iocs/blob/1a8384468dd292c6d2c5114c32e42dc0da1f5ae1/GREYVIBE/greyvibe.yara#L61-L73"
= "https://github.com/WithSecureLabs/iocs/blob/1a8384468dd292c6d2c5114c32e42dc0da1f5ae1/LICENSE"
= "c6fc0969bb62de731e9770447df565e427b03c69851708a0a30a4da20f176236"
= 75
= 75
= ""
strings:
$a = "// String Reconstruction"
$b = "Math.cos"
$c = "Math.sin"
$d = ".join(\"\")"
condition:
all of them
}
Strings (4 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $a | text | "// String Reconstruction" | |
| $b | text | "Math.cos" | |
| $c | text | "Math.sin" | |
| $d | text | ".join(\"\")" |
Condition
all of themIn plain words (Heuristic)
- All patterns in the rule must match.
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References
Licence & attribution
Author: WithSecure
Source repository: WithSecure Labs IOCs @ 1a8384468d
Licence: BSD 2-Clause License (repository licence)
Copyright notice: Copyright (c) 2022, WithSecure Oyj
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 9901d2df-6539-51c6-a24d-c06a7e898a6a
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