Is it necessary to use Malwarebytes in conjunction with Bitdefender?

Bitdefender alone is enough to combat malware with its robust behavior blocker, cloud-based detection, and signature-based detection. Also, it offers one of the best protections against blocking malicious/phishing websites. It is the only antimalware that has received the maximum number of awards from reputable antimalware testing agencies like AV-Test and AV-Comparatives.

You can still use Malwarebytes as a second opinion scanner, but make sure that you are using its free version, which does not have real-time protection available, or it may interfere with Bitdefender.

Adding to this, according to Malwarebytes, they remove malware detections from their database which are old (the time period is not specified), but when it comes to creating malware signatures, they do not create detection for samples found in the wild older than 3 months. They believe these will not cause any issues to the user, and this information is also mentioned in their online forum, which makes it a bit less trustworthy. Even if a user encounters an old ransomware, they simply ignore it. I have sent many samples of various ransomware that were older than 3 months at different times, but they refused to create detection since they said they are not seen in the wild anymore.

Furthermore, Malwarebytes mostly relies on its machine learning and artificial intelligence, which in turn creates a maximum number of false positives.

On the other hand, Bitdefender creates detections for each and every ransomware and malware it comes across, even if they are very old. Bitdefender never compromises on the security and protection of its users. Additionally, Bitdefender has the largest malware detection database among all its competitors. I am not here to cheer Bitdefender up, because no antimalware is 100% effective. Due to this, if anyone comes across any malware undetected by Bitdefender, unlike other antimalware vendors, Bitdefender also provides a URL where you can share the suspected malware sample with the Bitdefender malware research team.

In conclusion,

Main line of protection: Bitdefender

Second opinion scanner (if needed): Malwarebytes Free

@Alexandru_BD anything to add here

Regards