The good news is, dialups are relatively safe

PC Authority | Unprotected PCs fall to hacker bots in four minutes
The lifespan of a poorly protected PC connected to the internet is a mere four minutes, research released this week claims. After that, it's owned by a hacker.

In the two week test, marketing communications firm AvanteGarde deployed half a dozen systems in "honeypot" style, using default security settings. It then analysed the machines' performance by tallying the attacks, counting the number of compromises, and timing how long it took an attack to successfully hijack a computer once it was connected to the internet.

The six machines were equipped with Microsoft Windows Small Business Server 2003, Microsoft Windows XP Service Pack 1 (SP1), Microsoft Windows XP SP1 with the free ZoneAlarm personal firewall, Microsoft Windows XP SP2, Macintosh OS X 10.3.5, and Linspire's distribution of Linux.

Surprisingly, most of the machines resisted attacks for the two weeks of the trial, the XP machines because of the firewalls (yes, even the one that comes with XP works if it's turned on), Linux because it's, well, Linux, and the Mac because, although numerous bots tried, and many of them could have succeeded, all of them were Windows-targeted. One good Mac hacker could destroy the illusion that Macs are immune to such things--but who wants to put that much time into crippling 2% of the market?