Q We have an iPad and an iMac. An email footer contained a link to the Tennis Clubs website, which I tried to access on the iPad, only to be redirected to a sex chat site. I cleared the history and shut Safari down. When I tried to access the same site using Firefox on the iMac, Norton Internet Security identified it as dangerous, so I stopped. Another time I did get through to the real site without being redirected. Should I be concerned, and what should I do?

A You have already taken the most important action – backing off.

Some sites are regularly hacked, and this appears to be one of them. Provided that you keep your OS and browser up to date, such a brief and shallow contact with a possibly malevolent site should not put you at significant risk of acquiring anything unpleasant on either your Mac or iPad. The risks start to increase considerably when you ignore warnings and press on, visiting more pages in the site, and even worse viewing movies or other items from there. Any of those could easily contain Trojans which could cause you a problem.

Hacked sites are usually the result of their using old and vulnerable scripting support, such as an old version of PHP, or other software that has opened it to a hack. Only very rarely might this be the result of a hack into your ISP’s name server, and you can protect against that by using OpenDNS.

Comments If the site is relatively small or non-commercial, it is good to drop its webmaster an email to let them know of the problem, as they may be unaware. The police are usually only interested if there is serious criminal activity, such as paedophile porn, involved.

In this case, this appears to have been a genuine link in a genuine email. Always be suspicious of links contained in messages, and hover the pointer over them to see the true URL which they will take you to, or read the message as plain text, before clicking on the link.

Updated from the original, which was first published in MacUser volume 28 issue 09, 2012.