Because NIS is not particularly effective in protecting against malware, I purchased and installed Webroot SecureAnywhere, which, at least on initial running, found and eliminated a number of malware products. Norton, however, said that it didn't like coexisting with Webroot. I've uninstalled Webroot temporarily and am running Malwarebytes instead.
I queried Webroot about the conflict with NIS and received the following response from them:
We have been getting reports of Norton messages stating to remove Webroot SecureAnywhere from computers using both products. We know of no conflicts between Norton and Webroot SecureAnywhere and we are working to get Norton to remove this message from their product. You may wish to contact them as well, as they may be more responsive to requests from their customers. Norton can be reached at 1-800-927-3991. We apologize for the inconvenience. You can ignore the message from Norton.
Although security software companies have, traditionally, advised against running multiple antivirus programs on the same computer, this rule does not hold true for Webroot SecureAnywhere. The reason for such recommendations involved the way traditional antivirus programs run. SecureAnywhere is different.
Most antivirus software is very aggressive. When an antivirus program scans a file, it accesses that file and locks it until the scan is complete, so other programs can’t access it. If multiple real-time antivirus scanners are installed on the same system, the secondary system will attempt to scan the file the moment it is accessed by the first scan. Now, both programs are competing to scan the file. Depending on the aggressiveness of each program, one may detect the conflict as an “attack” and attempt to block the offending process. Now, the two antivirus programs are not only competing for the same file, but are actively working against one another. This causes a strong struggle for resources on your computer that can drastically impact system performance, and can leave your system more vulnerable to malware attacks.
Antispyware software, on the other hand, is non-aggressive toward antivirus software. While it may try to lock files being actively scanned, it will not compete with an antivirus program when the latter attempts to block or take control of a file. This is why antispyware applications can run alongside most antivirus protection without issue.
As mentioned above, Webroot SecureAnywhere works differently from other virus protection. SecureAnywhere does not rely on the customary system of definition sets to make determinations. Instead, this new program examines file behavior and system interaction closely to determine if files are malicious or not. Only files that present risk are examined.
Using the same advanced behavioral detection that determines which files are malicious, SecureAnywhere is able to recognize other virus protection software on your computer as one of “the good guys.” This means SecureAnywhere won’t block with on-access scanning or try to break through legitimate lockouts. In this way, potential software conflicts, and the resulting system slowness and vulnerability, can be avoided. You can run SecureAnywhere alongside another antivirus program safely.
If you have any other questions, we encourage you join the Webroot Community to see what other security experts and customers are saying.
Thank you,
The Webroot Support Team
I see no reason to doubt Webroot's contention. The question is not whether Webroot is right or wrong but, rather, whether NIS behaves differently (and less effectively) when both it and Webroot are installed. Or to put it another way, does NIS behave differently in any significant way when it detects the presence of Webroot.
Does anyone have an answer?
Thanks.