win_jfmbackdoor_auto

YARA detection rule by Felix Bilstein - yara-signator at cocacoding dot com · Unknown

Detects win.jfmbackdoor.

rule win_jfmbackdoor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.jfmbackdoor."
        info = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.6.0"
        signator_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.jfmbackdoor"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    


    strings:
        $sequence_0 = { 8d4540 6880000000 50 50 e8???????? 55 e8???????? }
                                                                                                
        $sequence_1 = { c1c105 81c19979825a 8b402c 89442444 8bc3 034c2444 33c2 }
                                                                                                
        $sequence_2 = { 8d4614 50 e8???????? 83c404 85c0 0f85fa050000 8d4614 }
                                                                                                
        $sequence_3 = { ba???????? b904000000 e9???????? ba???????? b908000000 e9???????? ba???????? }
                                                                                                
        $sequence_4 = { 8bf0 83c41c 85f6 0f8526030000 8d442464 c744242403000000 89442428 }
                                                                                                
        $sequence_5 = { e8???????? 83c404 c744240801000000 57 e8???????? 83c404 8d4620 }
                                                                                                
        $sequence_6 = { 8d854cfbffff 50 ff15???????? 85c0 0f84e8040000 80bd1ffbffff00 0f84de000000 }
                                                                                                
        $sequence_7 = { 8988f8010000 8990fc010000 85f6 7421 83c8ff f00fc14604 7517 }
                                                                                                
        $sequence_8 = { 8d5824 895c2418 3be8 7522 0f104058 0f11442424 0f104068 }
                                                                                                
        $sequence_9 = { ff15???????? 6689459a 8b8588fdffff 8bc8 898560fdffff 83781410 7208 }
                                                                                                
    condition:
        7 of them and filesize < 2339840
}

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

cd4218b9-fb9d-4481-a7c8-53b7313c93c8

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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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