This is purely an abstract and hypothetical question: it isn’t happening to me. I’m just curious…
Do various anti-virus programs bump into each other, knock each other over – “Warning: A Program is Altering Your Files” – well, yeah, it’s my other anti-virus app…
Or do the major ones, at least, offer “professional courtesy” to each other, so, like, Norton knows Malware Bytes when it sees it?
(Or…would that be a weakness some stinker could exploit?)
Different scanning engines can interfere with each other. Some anti-malware manufacturers will check for incompatible software and recommend you uninstall or uninstall it for you before they complete installation.
Anti-virus engines in particular cause problems.
If you do end up with two incompatible engines running, you likely won’t get a direct error message (X is interfering with Y) but you may get symptomatic errors that will help you track it down.
In my experience yes. Not necessarily direct error messages, but rather odd behavior that is resolved once one av is removed.
Interesting! Thanks! (It’s an obscure little item of ignorance…but it has now been fought!)
(I normally run AVG, but every now and then I also do a Malware Bytes scan. The two don’t seem to get in each other’s way, but I’m not sure I’d know what to look for.)
Malwarebytes is not sold as a substitute for an anti-virus program. It is designed to play nice with whatever your anti-virus is. You can run it together with any major anti-virus program. That is not to say that they don’t have an occasional bug, but if that happens the Malwarebytes people will make an effort to fix it. I run Malwarebytes Pro together with Avast on all my computers and all the computers that I have set up for others without any problems.
I am told by someone who used to work for an anti-virus company, that most of their large data center customers use at least two different anti-virus packages. I have no way to verify this for myself.
Personally, I once bought a laptop that came with a free 90-day trial of AVG. I didn’t realize that AVG somehow got activated and I installed Avast and Malwarebytes. The computer ran fine until the free trial expired and then I removed AVG.
As mentioned above, there are antivirus programs and there are anti-malware programs. Viruses are specifically designed to be malicious and destructive, to cause data loss and/or stop network throughput and to replicate themselves as quickly and numerously as possible. Malware is designed to steal data, to implant advertising, to hijack browsers, to hijack internet connections to cause denial of service attacks on other websites etc. Most antivirus suites will sometimes try to include anti-malware as well (and vice versa) but I’ve always stuck to using one good antivirus and a couple good anti-malware programs.
Antivirus are apps like AVG, Norton, Avast, McAfee, and ZoneAlarm (which started out as more an anti-malware firewall program but since has evolved into a decent antivirus as well).
Anti-malware apps include Malwarebytes, CCleaner, AdAware, SpyBot etc. I run all these periodically while running AVG constantly and they don’t conflict with each other.
I spent some weeks (several years ago) trying to work out an odd issue on some Windows servers. I seem to recall the user was reporting “File Not Found” errors for files that quite clearly existed. I tracked this down (via some deep digging with FileMon/RegMon) to the combination of an Antivirus scanner and (as I recall) an Open File Backup Agent.
<extremely simplified technical detail>Windows has a low level driver function called a “hook” - this lets you replace an existing API function with your own. So Antivirus programs will “hook” the FileOpen API, giving them the opportunity to scan the selected file prior to “chaining” to the original Windows API FileOpen function. The thing was, the Open File Backup Agent did the same thing, copying the opened file so that when the backup ran, it could access the (somewhat older) copy of the open file. One of the rules of writing a hook function is that you either pass through without changing anything, or you return a reasonable response back if you didn’t handle the request. So the hooks need to react just like the FileOpen API if they block or modify the call. In this case, the Antivirus program was returning a file handle but a status code that did not match, and the OFBA (that had also hooked the FileOpen API) was getting confused, and returning a “File Not Found” status to the calling application. Other AntiVirus agents were perfectly fine, because they were more careful about the way they handled the hook functions.
More good things to know! Thank you!
(si_blakely: Yikes! If that’s extremely simplified, I’m in deep trouble; I followed it, but only with difficulty. It makes me want to make a “machine language” joke, except I’d tell it wrong!)