win_megacortex_auto

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

Detects win.megacortex.

rule win_megacortex_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.megacortex."
        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.megacortex"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    


    strings:
        $sequence_0 = { 898554feffff 8b4518 56 898558feffff 8d855cfeffff 57 50 }
                                                                                                
        $sequence_1 = { b8ffffff7f d1ea 2bc2 3bc8 7607 8bc7 897dfc }
                                                                                                
        $sequence_2 = { f7da 1bd2 2bce 23ca 03c1 8906 8d45e8 }
                                                                                                
        $sequence_3 = { 897db0 8b5f04 8d7704 8b4508 8945cc 8b4d10 8d041e }
                                                                                                
        $sequence_4 = { 1bc9 23c8 8d45f8 8bd1 2bd0 85c9 b801000000 }
                                                                                                
        $sequence_5 = { e8???????? 8b85349cffff 8d8db09cffff 51 8d8d349cffff c645fc02 8b30 }
                                                                                                
        $sequence_6 = { 6a00 ff15???????? 3b7e30 0f8321140000 8b4e2c 8d462c 03c1 }
                                                                                                
        $sequence_7 = { ffb518ffffff e8???????? 83c418 8d8d5cfeffff 6a01 6a03 }
                                                                                    
        $sequence_8 = { eb0d 8b4304 03c9 83e001 0bc8 894b04 8b450c }
                                                                                                
        $sequence_9 = { c645fc06 e8???????? 57 ff15???????? e9???????? 56 8d8d50fdffff }
                                                                                                
    condition:
        7 of them and filesize < 1556480
}

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

2aa1325f-4085-48bd-bed2-1a81d982b3a8

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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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