Question

A detection engineer wrote a YARA-L single-event rule to flag PowerShell execution with the '-EncodedCommand' flag. The rule fires hundreds of times daily, almost entirely on a legitimate internal automation account that always runs encoded commands from a known management server. The engineer must reduce false positives without losing visibility into encoded PowerShell run by other principals or from other hosts. Which change to the rule is the MOST appropriate?

Accepted Answer

Add an exclusion condition in the events section that filters out the specific automation principal AND the known management hostname together, keeping all other encoded-PowerShell detections active

Answer

Raise the rule's severity threshold so the noisy alerts are suppressed in the alert queue while the rule continues to match every event

Answer

Broaden the regex on the command line so it matches only exact base64 strings, removing the '-EncodedCommand' flag check entirely

Answer

Disable the rule and rely on a curated detection set to cover encoded PowerShell activity instead