EXE_Unknown_Byakugan_April2024

YARA detection rule by Yashraj Solanki - Cyber Threat Intelligence Analyst at Bridewell · Unknown

Rule EXE_Unknown_Byakugan_April2024 (No description metadata provided).

import "pe"
rule EXE_Unknown_Byakugan_April2024 {
    meta:
        Description = "Detects Byakugan malware based on the PE properties"
        author = "Yashraj Solanki - Cyber Threat Intelligence Analyst at Bridewell"
        Reference = "https://www.fortinet.com/blog/threat-research/byakugan-malware-behind-a-phishing-attack"
        File_Hash = "9ef9bbfce214ee10a2e563e56fb6486161c2a623cd91bb5be055f5745edd6479"
        date = "2024-04-05"
        yarahub_author_twitter = "@RustyNoob619"
        yarahub_reference_md5 = "fd91bbc05f3c8cad2387ff0cac5747af"
        yarahub_uuid = "80f36486-0746-4f73-9b73-c8ab42dc5abb"
        yarahub_license = "CC0 1.0"
        yarahub_rule_matching_tlp = "TLP:WHITE"
        yarahub_rule_sharing_tlp = "TLP:WHITE"
    
    condition:
        (pe.imphash() == "4d0fb8dc9ee470058274f448bebbb85f"
        or pe.imphash() == "2905d3c578dd8f8b4132143b23256eb9")
        and pe.number_of_exports > 50
        and for 25 export in pe.export_details:
        (export.name startswith "??$" and export.name contains "@")
        and filesize > 20MB
        
 }

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

6b842f67-33d4-411f-aea0-3a2db09da2c4

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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

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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 ]]

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

[[ currentRule.title ]]

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