I've been using Kaspersky Internet Security for about 2 year now. Never had an issue with it, in fact I'm quite pleased with it... until recently. On all of my computers using KIS2011 (I have 3 running it) I have a little problem.

One of the patches for KIS2010 (yes, 2010, not 2011) had caused the program to once or twice a day take 100% of the CPU, usually when I'm playing a game. It's also caused a erratic speeds with my internet. Both of these problems have carried over into KIS2011 as well. I had my ISP out here because even the ISP thought the speed issue was their fault due to new lines they installed here, only to find out that if we just turn off Kaspersky altogether the problem goes away. So I thanked him KINDLY and sent him on his way and felt kind of silly for not trying that to begin with.

Ok, so I called Kaspersky's local tech support here, who are always really wonderful, but the techs seemed confused as to why this was happening. (They were only trained for 2010, SINCE 2011 hasn't been launched in Thailand yet.) He had me toy with some of KIS's firewall settings, to no avail. Then we shut off the firewall completely, no luck. So I just started shutting down KIS a piece at a time (very nice feature of KIS, lots of control) and found that it was in fact the 'Web Anti-Virus' feature that is slowing my connection down. With all other features on and that one off, everything works fine. Happy as always to tell tech support what their program is doing wrong, he seemed even more confused. "Eh... I'll call you back."

I'm still waiting. Haven't even addressed the 100% CPU problem yet.

Just kind of wanted this documented here in case anyone else runs into this. If I'm getting it on 3 computers, one of which never interacts or shares files with the other two, then sure I'm not alone.

If you do have some comment or a possible fix/solution, I'd be happy to hear it.Hey there.

I use KIS 9 (2010) as well.

The Web Antivirus is used to scan HTTP traffic for suspicious or malicious traffic.

It works with the Firewall, Network Attack Blocker, and several other components to block suspicious items.

Whenever you get suspicious activity like that, KIS begins to block that activity without notifying you. Only when it is malicious activity, KIS will pop up and tell you what's going on.

I would not put it past your network to be the target of an attack. KIS never works in overdrive, unless the network is under attack.

Recently, my brother's computer had been infected by a backdoor trojan. As being infected, the backdoor trojan was stealing massive bandwidth. With KIS on, it could detect if the network was being attacked, but not if the bandwidth was being stolen. So, in checking the latency, seems like it was way too high. After disinfecting my brother's computer, it appears the bandwidth returned to normal.

During the periods on which the backdoor trojan decided to steal bandwidth, my computer would slow down as well. And when processes were checked, seemed KIS was taking 60% memory usage, which was 45% more than what it usually takes.

The Web Antivirus is very aggressive, and doesn't just work on watching where you surf, it actually reads all threads coming through the HTTP PORTS, including those on the network.I still haven't heard back from them. Quite disappointing considering I've always had good experiences with their local tech support before. It's been a few days, so I think I'll give them a call back today and see if they have any more answers. I don't just get this issue at home, but anywhere I use the internet while KIS Web Scan is on. It doesn't matter what level of scanning either, even minimal scanning will still cause this.

Something else interesting it does. I have a 4Mb/600Kb ADSL connection at home (but it does this everywhere, just an example). When I do a speed test at home, I get LESS than 2Mb download speed for most of the test, then it shoots up to something insane like 30Mbps at the last second, giving me an inaccurate report. I've just tested this on other internet connections and found it doesn't just happen at home, but anywhere I'm using the internet.

Scanner on:


Scanner off:


Note that this is a 3Mb DSL line that I am on now, I'm not at home. I get the same kind of result from home though.

This happens on all three of my computers with KIS, including my laptop which we determined to be clean of viruses after this issue started (in fact, you helped me with that). I regularly do full scans weekly and KIS is always on except during World of Warcraft updates, because its application checker sometimes holds up WoW updates for too long and WoW thinks the update has failed and I have to start it again.You might want to post on the Kaspersky forum if you haven't already done so. I've always had excellent RESULTS there.