After hbaving just signed up with McAfee, I’m now getting the hard sell for a firewall. And, lately, a computer professional friend of mine said a firewall is an absolute must for Net surfers if I want to keep a hacker from rooting through my hard drive whenever I’m on line.
For the record, I use a v90 dial-up modem. And I thought the only people who are really vulnerable are PC users who have cable modems, DSL, and dial-up modem users who leave stay online for lengthy periods.
What’s the deal here? How hard–and how probable–is it for a hacker to search through my PC while I’m online?
I wouldn’t worry too much, unless you have a lot of sensitive or very important data. A single PC isn’t much use to a hacker, unless it contains valuable information or can be used as part of a distributed denial-of-service (DDOS) attack on another machine. However, a single home PC wouldn’t generally have the capacity to be useful for even that.
I certainly don’t worry; my only concession is to use ZoneAlarm, which is an idiot-proof freeware package that blocks access to ports you aren’t using (basically, you tell it which programs you want it to allow to connect to the internet from your PC, and it blocks everything else but the replies). Mind you, if that wasn’t freeware I wouldn’t even bother paying for it.
There’s two main ways someone could access your machine
If you have open shares on your computer. If you have NetBios over TCP enabled and you’re sharing your drives, they will be accessable to anyone over the Internet. There are NetBios scans going on all the time (I used to get several a day) so even if you’re only using dial-up, if you have open shares, they’re bound to be discovered eventually. Once an open share is located, script kiddies can put a backdoor trojan on your computer without your knowledge.
If you have a backdoor trojan on your computer, it can be set up to inform the script kiddie of your presence as soon as you go online and he can have full control of your computer until you disconnect, so again, only having a dial-up connection is not a significant protection.
A backdoor trojan is usually installed by running an executable from an untrusted source. Infection over an open share or an HTML exploit (like GodMessage) is also possible.
While the scenarios discussed above are possible, IMHO a firewall is not needed under your circumstances. Granted, it won’t hurt anything, so if it would make you feel better, get a free one from TheZone, but you shouldn’t need it. That is just my two cents, but a more prudent user might say better safe than sorry. The way I look at it, the less things I have running, esp. on the net, the better.
Quote: 2. If you have a backdoor trojan on your computer, it can be set up to inform the script kiddie of your presence as soon as you go online and he can have full control of your computer until you disconnect, so again, only having a dial-up connection is not a significant protection.
So unplug the thing and run a virus scan to get rid of it. No big deal. Even worse case scenario, someone takes control of my computer and I am unable to move five feet to yank the phone cord, what are they going to do? Steal my 12 year old copy of “Colonization”? Read my joke-of-the-day email? Read the opening paragraphs of a short story I was working on? So what.
It’s less necessary with a dial up to have a personal firewall, but not a bad idea. Since ZoneAlarm is free, go ahead and install it. It can also tell you things about legitimate software that you didn’t know.
Use it to create a distributed denial of service attack against Microsoft. You may have to have a conversation with your friendly local FBI agent.
One nice thing about a firewall–I use ZoneAlarm and highly recommend it–is that it controls traffic both in and OUT of your machine. It can block not only hackers but also the less malicious but still insidious spyware that tracks and reports your web surfing to advertisers (side note: Gibson Research Corp. http://www.grc.com distributes a freeware program called OptOut that will detect and remove spyware from your computer). And since it’s free for personal use, you’ve got absolutely nothing to lose by getting it.
You can test your security at the above mentioned grc site also; look for the ShieldsUP! link. I freely confess that I am a geek, I got a huge thrill from running the test and having it come back and tell me my machine is completely invisible to the outside world.
Unless you’re sharing with write-access (which would be incredibly stupid), the script kiddies can’t put shit on your computer through your shares.
Like the others have said, firewalls are not incredibly important to prevent cracking (though they do help, if you may inadvertently be running services). Not being stupid helps with that.
Firewalls are more useful for protecting against denial of service attacks, wherein a script kiddie will send a special packet or series of packets intended to crash your computer.
I never used a firewall when I was on dial-up. Hackers couldn’t care a less about someone with that slow of a connection. They are only interested in people that have a decent size pipe to the net so they don’t have to wait forever themselves…or at least thats what I understand
