Question malware autodelete

Yes, that scenario is possible in general terms, but not in the way many people assume.

Some malware families act as droppers. The initial file (for example something detected as Wacatac) may download and execute a second-stage payload. After execution, the dropper can delete itself to reduce forensic evidence. That part is normal behavior for many modern threats.

However, self-deletion does not mean “no trace” and it does not mean Defender or another AV will miss it completely.

A few important points:

First, antivirus detection is not limited to file presence. Modern Defender relies heavily on behavioral monitoring, process telemetry, memory inspection, and cloud-based detection. Even if the original file deletes itself, the following may still be logged:

– Process creation events
– Network connections
– Registry modifications
– Scheduled task creation
– Persistence mechanisms
– Defender detection telemetry in the cloud

Second, if the second-stage payload remains on disk or establishes persistence, that component can still be detected later. The disappearance of the dropper does not protect the payload.

Third, even if both the dropper and payload delete themselves, there will often still be artifacts such as:

– Prefetch entries
– Event logs
– Defender detection history
– MDE telemetry in the portal
– Suspicious command-line or PowerShell traces

In Microsoft Defender environments with cloud protection enabled, detection often happens at execution time, not only during scheduled scans. So even short-lived malware can still be detected and recorded.

The only scenario where “no trace” is more likely is if:

– The system is not onboarded to Defender for Endpoint
– Cloud protection is disabled
– Real-time protection is disabled
– Logging is severely limited
– The malware executed fully in memory without persistence

Even then, modern EDR solutions usually retain some telemetry.

So yes, malware can delete itself. But no, that does not automatically mean it leaves zero trace or becomes invisible to future scans. Detection is not purely file-based anymore.