MAL_LNX_Perfctl_Oct24_RID2E56

YARA detection rule by Florian Roth · CC-BY-NC https://creativecommons.org/licenses/by-nc/4.0/

Detects Perfctl malware samples

rule MAL_LNX_Perfctl_Oct24_RID2E56 : DEMO FILE LINUX MAL {
   meta:
      description = "Detects Perfctl malware samples"
      author = "Florian Roth"
      reference = "https://www.aquasec.com/blog/perfctl-a-stealthy-malware-targeting-millions-of-linux-servers/"
      date = "2024-10-09 11:10:11"
      score = 75
      customer = "demo"
      license = "CC-BY-NC https://creativecommons.org/licenses/by-nc/4.0/"
      hash1 = "a6d3c6b6359ae660d855f978057aab1115b418ed277bb9047cd488f9c7850747"
      hash2 = "ca3f246d635bfa560f6c839111be554a14735513e90b3e6784bedfe1930bdfd6"
      tags = "DEMO, FILE, LINUX, MAL"
      minimum_yara = "3.5.0"
      
   strings:
      $op1 = { 83 45 f8 01 8b 45 f8 48 3b 45 98 0f 82 1b ff ff ff 90 c9 c3 55 } 
      $op2 = { 48 8b 55 a0 48 01 ca 0f b6 0a 48 8b 55 a8 89 c0 88 4c 02 18 8b 45 fc 83 e0 3f } 
      $op3 = { 88 4c 10 58 83 45 f8 01 83 7d f8 03 0f 86 68 ff ff ff 90 c9 c3 55 } 
      $op4 = { 48 83 ec 68 48 89 7d a8 48 89 75 a0 48 89 55 98 48 8b 45 a8 48 8b 00 83 e0 3f 89 45 fc } 
   condition: 
      uint16 ( 0 ) == 0x457f and filesize < 300KB and 2 of them
}

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

cfe3e055-b6ff-49b0-bc87-8ea2f1111017

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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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