A security analyst identifies a device on which different malware was detected multiple times, even...

Reimaging the device is the most effective way to eliminate persistent malware because some sophisticated malware, such as rootkits and firmware-level threats, can survive traditional scans and removals.

If a system keeps getting reinfected after cleaning, it may indicate a deeply embedded persistent threat, possibly in:

The Master Boot Record (MBR) or EFI firmware.

A compromised system restore point.

A hidden backdoor left by the malware.

Why Not Other Options?

A (Update and scan in safe mode) → Might help, but if malware is persistent, it will likely return.

C (Upgrade OS) → Does not necessarily remove malware; some malware survives OS upgrades.

D (Secondary scanner) → Useful for detection but does not guarantee complete removal.

Best Practice:

Replace the hard drive to eliminate firmware-level infections.

Reimage the system from a known-good source.

Update the OS and security patches before reconnecting to the network.