Passwords: Choose strong passwords. A sequence of random upper and lower case letters, mixed with numbers and special characters is better than simple, single words or names that are easy to guess. Do not use the same password for critical sites as for casual throwaways.
In public places with open wireless: Do not do anything important. Make sure that connections use HTTPS (HyperText Transfer Protocol with Security). Your browser will show that you are connected with the HTTPS, and you can see an icon of a closed lock which indicates that the link is encrypted. But HTTPS only encrypts the contents.
Attachments and downloading or installing: Do not click on to view attachments from strangers, or unexpected attachments from friends; don't automatically accept, click, or install when requested. Don't download programs of dubious provenance. Be wary about downloading and installing any software unless it comes from a trusted source.
Windows and Microsoft Office programs: Use anti-virus software. Keep it up to date. Do not click on the sites that offer to run a security check on you computer. Turn off macros in Microsoft Office programs. Disable ActiveX as much as you can. Keep other software, like browser and operating system, up to date.
Cautious:
Turn off pop-ups and third-party cookies. You should set up defenses for each browser you use.
Use add-ons like Adblock and Flashblock to reject advertising images.
Use a spam filter on your mail.
Turn off JavaScript in Adobe Reader.
Turn off services that you don't use.
Turn on the firewall on your computer. It is a software that monitors incoming and outgoing network connsctions, and blosks those that violate access rules.
Use two-factor authentication on your important accounts if available.
Paranoid:
Disable HTML and JavaScript in your mail reader.
Use NoScript to limit JavaScript, and Ghostery to disable trackers.
Turn off all cookies except for sites that you permit.
Use less-frequently targeted systems (Linux or Mac OS X, instead of Windows; Chrome, Firefox, Safari or Opera instead of Internet Explorer...)
The same precautions apply to cell phones, too.
Source:
Brian W. Kernighan. D Is for Digital
–What a Well-Informed Person Should Know About Computers and Communications. Published by DisforDigital.net; 2011. ISBN-13: 978-1463733896
ISBN-10: 1463733895, pp. 177-178.
