win_mailto_auto

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

Detects win.mailto.

rule win_mail_o_auto {

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

    


    strings:
        $sequence_0 = { eb12 41b849040000 488d154eef0b00 e8???????? f6430801 488b4c2450 7416 }
                                                                                                
        $sequence_1 = { e8???????? 85c0 7513 c744242010010000 41b8a3000000 e9???????? 488b06 }
                                                                                                
        $sequence_2 = { 7504 8bda eb09 488b442450 48635820 488d052dd50b00 4a8b04f8 }
                                                                                                
        $sequence_3 = { eb2f c7839800000002000000 b880020000 41b870000000 eb18 b85a020000 41b866000000 }
                                                                                                
        $sequence_4 = { eb5d 4d85d2 740f c744242885070000 ba32000000 eb43 83b9ec06000000 }
                                                                                                
        $sequence_5 = { eb5a c7442428a10d0000 ba50000000 41b9f9000000 41b87e010000 48896c2420 e8???????? }
                                                                                                
        $sequence_6 = { 488d0d13951500 eb92 488d1512961500 488d4c2440 e8???????? 85c0 0f84da000000 }
                                                                                                
        $sequence_7 = { 898ab4000000 8bce c1e903 33c8 418bc3 338c24a0000000 898ab8000000 }
                                                                                                
        $sequence_8 = { c7870802000001000000 eb30 c7870802000002000000 eb14 483bce 7407 b837000000 }
                                                                                                
        $sequence_9 = { e9???????? 8b8784010000 898380100000 488b87e8030000 b905000000 4c89a42450010000 f6407c07 }
                                                                                                
    condition:
        7 of them and filesize < 5985280
}

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

3e673c73-b656-476e-b60e-40ee98ca6ff0

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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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