EXE_Unknown_Backdoor_March2024

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

Rule EXE_Unknown_Backdoor_March2024 (No description metadata provided).

import "math"
import "pe"
rule EXE_Unknown_Backdoor_March2024 {
    meta:
        Description = "Detects an unknown backdoor"
        author = "Yashraj Solanki - Cyber Threat Intelligence Analyst at Bridewell"
        Credits = "@naumovax for sharing the malware sample on Twitter"
        Reference = "https://twitter.com/naumovax/status/1765723034369872043"
        Hash = "ddf7b9bf24b19ee183d788f482a01e517048587e8ce21f5d32c927f6f0371824"
        date = "2024-03-07"
        yarahub_author_twitter = "@RustyNoob619"
        yarahub_reference_md5 = "ab3b45315e4054bf80adea0e2646ff32"
        yarahub_uuid = "c821b404-58c7-411d-bad6-ebf27e7d7337"
        yarahub_license = "CC0 1.0"
        yarahub_rule_matching_tlp = "TLP:WHITE"
        yarahub_rule_sharing_tlp = "TLP:WHITE"
    
    strings:
        $str1 = "sNbUdD"
        $str2 = "U,.-.._"

    condition:
        pe.number_of_sections == 3
        and for any section in pe.sections:
        (math.entropy(section.raw_data_offset, section.raw_data_size) > 7.84)
        and pe.imports("KERNEL32.DLL","VirtualAlloc")
        and pe.imports("KERNEL32.DLL","VirtualProtect")
        and pe.imports("KERNEL32.DLL","GetProcAddress")
        and pe.imports("ADVAPI32.DLL","DeleteService")
        and pe.imports("SHELL32.DLL","ShellExecuteA")
        and pe.imports("MSVCRT.DLL","printf")
        and pe.imports("WS2_32.DLL",116)         and all of them

}

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

51fee9ed-3d5e-4aad-b03f-d467b3631779

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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 ]]

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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 ]]

What do these messages mean?

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

[[ currentRule.title ]]

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