Ms13089 ransomware

Who Ms13089 is

MS13089 is a newly emerged ransomware group (first observed December 2025) that named itself after a 2013 Microsoft Security Bulletin, claiming a handful of victims including a law firm, operating primarily as a double-extortion actor.

Recorded activity

Disclosures attributed to Ms13089 in this database run from December 2025 to August 2026, totalling 5 victims — 0% of everything tracked here. Ms13089 has listed victims in 5 countries in this database, most often Chile, followed by United States and Germany. The sectors appearing most in its listings are Business Services, Other, Consumer Services.

Indicators of compromise

• [email protected]

Showing a sample of 1 EMAIL on file. Hashes and network indicators published for Ms13089. Leak-site addresses are deliberately excluded. Indicators age quickly — treat a match as a starting point for investigation, and an absence of matches as no assurance.

YARA detection rules

/*
ms13089 ransomware
*/

rule ms13089_Ransomnote
{
    meta:
        author = "ransomware.live"
        family = "ransomware.ms13089"
        description = "Detects ms13089 ransomware ransom note or artifact"
        date = "2026-05-04"
        severity = 7
        score = 70

    strings:
        $name1 = "ms13089" ascii nocase
        $name2 = "MS13089" ascii
        $onion  = "ms13089.onion" ascii nocase

    condition:
        any of them
}

Community-contributed rules for Ms13089, reproduced as published. Test them against your own corpus before relying on them: rule quality and false-positive behaviour vary by author.