This ISH Tecnologia Yara rule, detects the main components of the first version of RALord Ransomware

Hunt Hypothesis

This hunt hypothesis targets adversary behavior involving the deployment and execution of initial RALord ransomware components to identify early-stage infection indicators within the environment. Proactive hunting for these specific Yara signatures in Azure Sentinel is essential because detecting the first version’s core elements allows the SOC team to isolate threats before they escalate into full-scale encryption events that could compromise critical business operations.

YARA Rule

rule MAL_WIN_Ralordv1_Apr25 {
    meta:
        description = "This ISH Tecnologia Yara rule, detects the main components of the first version of RALord Ransomware"
        author = "0x0d4y-Icaro Cesar"
        date = "2025-04-01"
        score = 80
        reference = "https://ish.com.br/wp-content/uploads/2025/04/RALord-Novo-grupo-de-Ransomware-as-a-Service-1.pdf"
        hash = "BE15F62D14D1CBE2AECCE8396F4C6289"
        id = "67254633-3597-4770-9806-8b2e26c8f66a"
        license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"
        rule_matching_tlp = "TLP:WHITE"
        rule_sharing_tlp = "TLP:WHITE"
        malpedia_family = "win.ralord"

    strings:
        $code_pattern_quarterround = { 4? 31 ?? 48 8b ?? ?? ?? 4? 31 ?? 48 8b ?? ?? ?? 31 e8 4? 31 ?? 41 c1 ?? 0c c1 ?? 0c c1 ?? 0c 48 89 c2 c1 ?? 0c }
        $code_pattern_custom_alg = { 0f 57 ?? 0f 10 ?? c5 ?? ?? ?? ?? 0f 57 ?? 0f 10 ?? c5 ?? ?? ?? ?? 0f 57 ?? 0f 10 ?? c5 ?? ?? ?? ?? 0f 57 ?? 0f 11 ?? c5 ?? ?? ?? ?? 0f 11 ?? c5 ?? ?? ?? ?? 0f 11 ?? c5 ?? ?? ?? ?? 0f 11 ?? c5 ?? ?? ?? ?? 48 83 c0 08 48 3d 8? }
        $ralord_str_I = "chacha" ascii
        $ralord_str_II = "scorp" ascii
        $ralord_str_III = "RALord" ascii
        $ralord_str_IV = "onion" ascii
        $ralord_str_V = "/rust" ascii
        $ralord_str_VI = "BCryptGenRandom" ascii

    condition:
        uint16(0) == 0x5a4d and
        all of ($code_pattern_*) and
        4 of ($ralord_str_*)
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

Microsoft Defender for Endpoint — Custom indicators / advanced hunting
Email Gateway — Attachment scanning
File Share Monitoring — Periodic scanning of shared drives
YARA CLI — Manual threat hunting on endpoints

This rule contains 8 string patterns in its detection logic.

References

False Positive Guidance

Here are 5 specific false positive scenarios for the RALord Ransomware detection rule, tailored for a legitimate enterprise environment:

Scenario: Deployment of legacy backup agents or document management systems that utilize similar cryptographic signatures.
- Context: Enterprise environments often run older versions of tools like Veeam Backup & Replication, Acronis Cyber Protect, or Microsoft SharePoint services which may share code libraries with the first version of RALord, triggering the Yara rule on their installation binaries (e.g., vbr.exe, acronis_agent_service).
- Suggested Filter/Exclusion: Add a whitelist exclusion for specific file hashes or paths associated with these known good applications. For example: exclude if path contains "C:\Program Files\Veeam" OR hash in [known_good_hashes_list].
Scenario: Execution of scheduled administrative maintenance jobs involving database indexing or log rotation.
- Context: Scheduled tasks running under the Local System or Network Service accounts (e.g., SQL Server Maintenance Plans, Windows Task Scheduler jobs for sqlagent.exe) often generate temporary executable artifacts in system directories that mimic the component structure of RALord’s initial payload.
- Suggested Filter/Exclusion: Create a rule exception based on the running process parentage and user context: exclude if parent_process_name is "Task Scheduler" AND user_account contains "SYSTEM".
Scenario: Installation or update of third-party endpoint protection suites with embedded scanning engines.
- Context: Major security vendors like CrowdStrike, SentinelOne, or Symantec Endpoint Protection often include internal modules that utilize similar PE (Portable Executable) headers and string patterns found in RALord’s first version, causing alerts during agent updates or real-time scanning scans.