Backdoor:Linux/Gafgyt.J!MTB - Windows Defender Threat Analysis

Backdoor:Linux/Gafgyt.J!MTB is a critical variant of the Gafgyt botnet malware family targeting Linux systems, often IoT devices. This backdoor grants attackers remote control over compromised systems, enabling activities like C2 communication via HTTPSTOMP, bypassing security controls, and disabling competitor services. Its detection via concrete signatures and behavioral analysis indicates a high-confidence threat.

No specific strings found for this threat

rule Backdoor_Linux_Gafgyt_J_2147818960_0
{
    meta:
        author = "threatcheck.sh"
        detection_name = "Backdoor:Linux/Gafgyt.J!MTB"
        threat_id = "2147818960"
        type = "Backdoor"
        platform = "Linux: Linux platform"
        family = "Gafgyt"
        severity = "Critical"
        info = "MTB: Microsoft Threat Behavior"
        signature_type = "SIGNATURE_TYPE_ELFHSTR_EXT"
        threshold = "3"
        strings_accuracy = "High"
    strings:
        $x_1_1 = "HTTPSTOMP" ascii //weight: 1
        $x_1_2 = "OVHKILL" ascii //weight: 1
        $x_1_3 = "CFBYPASS" ascii //weight: 1
        $x_1_4 = "NFOKILL" ascii //weight: 1
    condition:
        (filesize < 20MB) and
        (3 of ($x*))
}

Immediately isolate the infected Linux system to prevent further network compromise. Deploy an updated Linux-compatible antivirus/EDR solution for thorough scanning and removal of the Gafgyt malware. Investigate and patch the initial compromise vector, reset all affected credentials, and strengthen network security controls for all Linux and IoT devices.