win_cryptowall_auto

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

Detects win.cryptowall.

rule win_cryptowall_auto {

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

    


    strings:
        $sequence_0 = { 8d540902 52 8b450c 50 8b4d08 51 e8???????? }
                                                                                                
        $sequence_1 = { 51 6a00 e8???????? 8b5018 52 }
                                                                        
        $sequence_2 = { 8bec 51 8b450c 83e801 234508 7418 }
                                                                                    
        $sequence_3 = { 8b4508 8b4cd004 51 e8???????? 83c404 ebda }
                                                                                    
        $sequence_4 = { 8b4514 50 8b4d10 83c101 51 8b550c }
                                                                                    
        $sequence_5 = { 7502 eb09 b801000000 85c0 759f }
                                                                        
        $sequence_6 = { ffd2 8b4514 50 8b4d10 51 8b5518 52 }
                                                                                                
        $sequence_7 = { 8b483c 51 e8???????? 83c408 3b4508 751c }
                                                                                    
        $sequence_8 = { e8???????? 83c408 e9???????? 837d0c02 752e }
                                                                        
        $sequence_9 = { e8???????? 8b10 ffd2 8b45f8 }
                                                            
    condition:
        7 of them and filesize < 417792
}

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

ef01bcae-9dab-46f0-acf5-9b0859a0434f

Propose edits, view related rules, and engage with the community through comments.

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 ]]

Community Discussion