I think my device is already infected

Something feels wrong — it's slower than it should be, there are popups appearing out of nowhere, your browser redirects to sites you didn't visit, or your antivirus flagged something it couldn't fully remove. This is a different problem than choosing protection for a clean machine.

Quick answer

Device is showing symptoms right now→Malwarebytes — run the free scan first, it finds what others miss

Mac showing strange behavior→Intego — built for Mac-specific threats that general tools skip

After cleanup, need ongoing protection→Bitdefender — add real-time protection once the machine is clean

This fits you if

Real-time antivirus blocks threats at the door — it's not primarily designed to extract embedded malware
Cleanup scanners like Malwarebytes go deep: they find adware, PUPs, rootkits, and stubborn malware that standard AV ignores
If your machine was already compromised before you installed protection, your existing AV may have missed the original threat

When it matters

There's an important distinction between two situations: a clean machine that needs protection going forward, and a machine that's already compromised. The cleanup scenario requires a different tool.

Real-time antivirus blocks threats at the door — it's not primarily designed to extract embedded malware
Cleanup scanners like Malwarebytes go deep: they find adware, PUPs, rootkits, and stubborn malware that standard AV ignores
If your machine was already compromised before you installed protection, your existing AV may have missed the original threat
On Macs: general-purpose antivirus often misses Mac-specific adware — a Mac-focused tool makes a real difference

Run the cleanup scan first. Then decide what long-term protection fits. These are two separate decisions.

When it fails

Deep rootkits that have embedded into the OS — no scanner can guarantee full removal at that level
Hardware-level firmware infections — rare, but not fixable with software alone
Damage already done: files encrypted by ransomware before it was caught, credentials already exfiltrated

If Malwarebytes finds nothing but symptoms persist, the infection may be deeper than any software can safely reach. In that case, a clean OS reinstall is the honest answer — not running more scanners.

How providers fit

Malwarebytes fits if your device is showing active symptoms. The free version runs a full on-demand scan and removes what it finds. It's the most trusted tool specifically for this scenario — used as a first-response scanner by IT professionals for years.

Intego makes more sense if you're on a Mac. Most general-purpose scanners don't catch Mac-specific adware and malware. Intego was built for macOS from the ground up — it finds things that cross-platform tools skip.

Bitdefender fits after cleanup — not during it. Once the machine is clean, add real-time protection to prevent reinfection. Bitdefender's detection rates and behavioral monitoring are where it earns its place.

Bottom line

Malwarebytes first, always. Run the free scan. If it finds and removes the problem, add Bitdefender for ongoing protection. If it finds nothing and symptoms persist, consider a reinstall before adding more software on top of a compromised system.

Quick decision: my device is infected right now→I need protection that won't slow things down after cleanup→Strong real-time protection once the machine is clean→