Q: Antivirus for MacBook Air?

darrengbl wrote:

 

May I know what ClamXav can do - it works just like other AV? Can the ClamXav be use for - Blocking virus, Real time safeguards, Two-way firewall, Scanning the system, etc?

ClamXav uses the cross-platform clamav scan engine which is almost exclusively a signature based anti-malware system. It does have some heuristic analysis capability, primarily in the phishing area for e-mail and web sites. ClamXav also has an optional real-time watch application called Sentry built into the full version available for download from the web (as opposed to the more limited AppStore version). It is not plug and play in that most options default to off, so you do have to do some minor tayloring at installation time to meet your particular needs. There is no firewall (OS X has it's own one-way). Lion OS will take care of all the blocking you need. Scanning is limited to files you have read access to, each user must scan their own files (home directory) and there are a few systems files (most in the underlying unix sub-system) that can't be scanned. Manual scanning can be initiated via the app or using a contextual service menu. There are also scheduled scanning and definitions updating options. Found malware can be automatically quarantined or deleted, but that's not recommended if you choose to scan e-mail content for malware and phishing. That's generally true for any AV (A-M) software as it will generally damage your mailbox index or worse.

I've used it for years, with no issues, to scan incoming mail and downloads. 

Does it slow down your Mac when running scans?

From what I gather, those who want free antivirus usually go with Sophos or ClamAV. On the other hand, those who need more robust antivirus for Mac usually go with Intego. It seems to depend on need and on the type of Mac security software someone is looking for.

 

Does it slow down your Mac when running scans?

 

From what I gather, those who want free antivirus usually go with Sophos or ClamAV. 

I don't have it do whole disk scans, just mail and downloads.  It's quick to do those, and I have not noticed any performance impact.

ClamXav, while free to use, is also donation-ware, which I've supported.

Tycoon24 wrote:

 

Does [ClamXav] slow down your Mac when running scans?

I'll offer my experience, although I'm probably a poor example as I'm still using a slow iMac G5 these days.

I have ClamXav, MacScan, Sophos and VirusBarrier X5 installed with background scanning turned off on all of them. I occasionally run manual scans with each of them, mostly just as tests. I've never measured the differences (probably should if I had time), but subjectively they all have about an equal impact on CPU use, so if I'm using any of them to scan lots of files, I leave it to an overnight session. None of them slow me down as much as either TimeMachine backups or MobileMe updates, but of course those go quicker.

Another resource question would be how much RAM do they use, which again I have never accurately measured. I do know that ClamXav Sentry (the real-time-scanner) uses a significant amount of RAM because the entire signature database is loaded. This allows it to rapidly scan files which means no slow down, as long as you aren't trying to watch the entire hard drive. The OS produces an amazing amount of temporary files, so if you are trying to scan each of them it will be noticeable and it will fill up the scan log.

darrengbl wrote:

 

Do you think real-time watch is necessary to keep the Mac form any harm?

It depends on a number of things. If you are running Snow Leopard or Lion, don't frequent sketchy software pirate sites (i.e. download all files and software from trusted sites), don't automatically click OK on warning dialogs that you don't understand and don't exchange files with WIndows users routinely then I would say no, not at this time. The protection provided in the current OS X is adequate to keep up with most users, but the bad guys are getting smarter about how to work around some of the protection and trick users into infecting themselves.

There are some settings that we are finding can be adjusted to help the inexperienced user, and you will find such things scattered around the forum. I noticed that Klaus1 has updated his tips which covers some of this Viruses, Trojans, Malware - and other aspects of Internet Security