There is "an easy and highly accurate" test to determine if a website contains malware. Click HERE to read the full report on Eastman's Online Genealogy Newsletter.
NOTE: "malware" is an abbreviation for "malevolent software." It refers to viruses, worms, trojan horses, and all other software that is designed to do nasty things to your computer.
Keep in mind that no anti-virus/anti-malware program is perfect. At best, all of them only detect 90% to 95% of the problems.