Black Revolution DDoS Malware. http://www.arbornetworks.com/asert/2013/05/the-revolution-will-be-written-in-delphi/

Hunt Hypothesis

The Black Revolution DDoS Malware is likely being used to compromise systems and launch distributed denial-of-service attacks by leveraging compromised hosts to overwhelm target networks. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate potential large-scale DDoS threats before they cause significant service disruption.

YARA Rule

rule BlackRev
{
   meta:
      author = "Dennis Schwarz"
      date = "2013-05-21"
      description = "Black Revolution DDoS Malware. http://www.arbornetworks.com/asert/2013/05/the-revolution-will-be-written-in-delphi/"
      origin = "https://github.com/arbor/yara/blob/master/blackrev.yara"

   strings: 
      $base1 = "http"
      $base2 = "simple"
      $base3 = "loginpost"
      $base4 = "datapost"

      $opt1 = "blackrev"
      $opt2 = "stop"
      $opt3 = "die"
      $opt4 = "sleep"
      $opt5 = "syn"
      $opt6 = "udp"
      $opt7 = "udpdata"
      $opt8 = "icmp"
      $opt9 = "antiddos"
      $opt10 = "range"
      $opt11 = "fastddos"
      $opt12 = "slowhttp"
      $opt13 = "allhttp"
      $opt14 = "tcpdata"
      $opt15 = "dataget"

   condition:
      all of ($base*) and 5 of ($opt*)
}

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 19 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Scenario: Scheduled System Maintenance Job
  Description: A legitimate scheduled task using schtasks.exe to perform system maintenance (e.g., disk cleanup, log rotation) may trigger the rule due to similar command-line patterns.
  Filter/Exclusion: Exclude processes initiated by schtasks.exe with known maintenance job names or check for --schedule or --trigger command-line arguments.

• Scenario: Database Backup Using SQL Server Agent
  Description: A SQL Server Agent job running a backup script may generate network traffic that resembles C2 communication.
  Filter/Exclusion: Exclude traffic originating from SQL Server services (sqlservr.exe) or use a filter based on the destination IP being a known internal database server.

• Scenario: Admin Task Using PowerShell for Log Analysis
  Description: An administrator may use PowerShell (powershell.exe) to analyze logs or perform system diagnostics, which could resemble malicious script execution.
  Filter/Exclusion: Exclude processes launched by powershell.exe with command-line arguments containing Get-EventLog, Get-Log, or Export-Csv.

• Scenario: Network Monitoring Tool Traffic
  Description: A network monitoring tool like Wireshark or SolarWinds may generate traffic that matches the detection logic due to similar packet patterns.
  Filter/Exclusion: Exclude traffic from known monitoring tools by checking the source or destination process names (e.g., wireshark.exe, solarwinds.exe).

• Scenario: Legitimate Delphi Application Communication
  Description: A legitimate Delphi-based application (e.g., a custom internal tool) may use similar network communication patterns as the Black Revolution malware.
  Filter/Exclusion: Exclude traffic from known internal Delphi applications by checking the process name or using a whitelist of allowed Delphi-based tools.