malware_asyncrat

YARA detection rule by JPCERT/CC Incident Response Group · NOASSERTION

detect AsyncRat in memory

rule malware_asyncrat {
    meta:
        description = "detect AsyncRat in memory"
        author = "JPCERT/CC Incident Response Group"
        rule_usage = "memory scan"
        reference = "internal research"
        hash1 = "1167207bfa1fed44e120dc2c298bd25b7137563fdc9853e8403027b645e52c19"
        hash2 = "588c77a3907163c3c6de0e59f4805df41001098a428c226f102ed3b74b14b3cc"

    strings:
        $salt = {BF EB 1E 56 FB CD 97 3B B2 19 02 24 30 A5 78 43 00 3D 56 44 D2 1E 62 B9 D4 F1 80 E7 E6 C3 39 41}
        $b1 = {00 00 00 0D 53 00 48 00 41 00 32 00 35 00 36 00 00}
        $b2 = {09 50 00 6F 00 6E 00 67 00 00}
        $s1 = "pastebin" ascii wide nocase
        $s2 = "pong" wide
        $s3 = "Stub.exe" ascii wide

    condition:
        ($salt and (2 of ($s*) or 1 of ($b*))) or (all of ($b*) and 2 of ($s*))
}

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

2919127c-69b1-4bf6-82b5-f7f6b923f5db

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

[[ reason ]]

What does this mean?

Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

[[ reason ]]

What do these messages mean?

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

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