MAL_Loader_KrustyLoader_strings

YARA detection rule by @petermstewart · GPL-2.0

Matches strings found in KrustyLoader malware samples.

rule MAL_Loader_KrustyLoader_strings {
  meta:
    description   = "Matches strings found in KrustyLoader malware samples."
    last_modified = "2024-03-25"
    author        = "@petermstewart"
    DaysofYara    = "85/100"
    sha256        = "030eb56e155fb01d7b190866aaa8b3128f935afd0b7a7b2178dc8e2eb84228b0"
    ref           = "https://www.synacktiv.com/en/publications/krustyloader-rust-malware-linked-to-ivanti-connectsecure-compromises"

  strings:
    $a1 = "|||||||||||||||||||||||||||||||||||"
    $a2 = "/proc/self/exe"
    $a3 = "/tmp/"
    $a4 = "TOKIO_WORKER_THREADS"

  condition:
    uint32(0) == 0x464c457f and
    all of them
}

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

ee818049-a032-48fd-8cbb-d5a542d663a0

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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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