How Human Analysts and Automation Work Together to Hunt Threats

Summary
The article explains how human context and experience complement automated threat detection, using Emotet examples such as suspicious services, Scheduled Tasks, registry keys and AppData files to illustrate analyst-led investigation.
Key points
- The article argues that automation can identify known patterns at scale, while human analysts can assess context and investigate suspicious activity that does not match existing rules or signatures.
- A Word process spawning cmd.exe is offered as an example of suspicious behavior that requires contextual judgment.
- Emotet may use randomly named files in AppData, Scheduled Tasks, registry Run keys and Windows services, and can spread through accessible administrative shares.
- Analysts can investigate services with duplicate descriptions and suspicious executable paths; the article describes an AppData\Local file that analysts considered likely Emotet.
- The article notes that malware changes can evade signature-based detection and that automated scoring thresholds may leave unknown files unflagged.
Article Details
- Defense Focus
- Combine automated detection with human analysis to identify and validate suspicious activity, investigate context, and improve detections as new malware variants emerge.
- Detection Methods
- Review service entries for randomly named services with duplicate descriptions copied from legitimate services.
- Inspect executable paths for Emotet-like artifacts in AppData\Local or AppData\Roaming, including files that mimic known executable names.
- Review newly created Scheduled Tasks and Registry Run keys, using known-bad lists while validating suspicious entries in context.
- Inspect suspicious files' security tab and certificate information for abnormalities.
- Correlate file, persistence, and service indicators with analyst experience; the article notes that an example file had no antivirus alert.
- Data Sources
- Windows service entries and service descriptions in the Service Manager snap-in
- Executable file paths and files in AppData\Local, AppData\Roaming, and system root directories
- Scheduled Tasks
- Registry Run keys and values
- File security-tab and certificate information
- Antivirus alerts and file signature or indicator scores
- Rule Types
- Known-bad lists
- Pattern-match or signature-based automated detection
- Automated scoring based on file indicators and attributes
- Platforms
- Huntress platform
- Defensive Actions
- Combine automation with human review rather than relying solely on automated alerts or signatures.
- Investigate suspicious service descriptions, executable paths, persistence entries, and file certificate attributes even when antivirus has not alerted.
- Use analyst findings on newly identified malware variants to update detections and retroactively apply them across systems.
MITRE ATT&CK
T1021.002 · SMB/Windows Admin SharesThe article says Emotet services attempt to propagate through accessible administrative shares.T1027 · Obfuscated Files or InformationThe article describes layers of nested obfuscation that some automated scanners could not analyze.T1053.005 · Scheduled TaskThe article says Emotet persistence can use Scheduled Tasks.T1055 · Process InjectionThe described fileless-malware example reflectively loads C# assemblies.T1059.001 · PowerShellA described fileless-malware example calls PowerShell to download and reflectively load C# assemblies.T1059.005 · Visual BasicA described fileless-malware example uses VBScript, which then calls PowerShell.T1543.003 · Windows ServiceThe article describes Emotet creating randomly named files in system root directories that run as Windows services.T1547.001 · Registry Run Keys / Startup FolderThe article says Emotet persistence can use Registry Run keys.
People
Malware
Dridexmalware strains onto a compromised host. Sometimes, it’s other well-known strains such as Trickbot or Dridex, other times it’s highly destructive ransomware like Ryuk. The good news is that Emotet isn’t invisible;EmotetIf you really want to see our SOC team in action, let’s dive into this example of Emotet, a well-known trojan that continues to evade security products—which CISA warned us of last year.Ryukother well-known strains such as Trickbot or Dridex, other times it’s highly destructive ransomware like Ryuk. The good news is that Emotet isn’t invisible; it does leave traces that can be detected if you know whatTrickBotmultiple malware strains onto a compromised host. Sometimes, it’s other well-known strains such as Trickbot or Dridex, other times it’s highly destructive ransomware like Ryuk. The good news is that Emotet isn’t