I originally published this blog at

December 02 2008, 10:32 AM         by         Benjamin Googins

Over Thanksgiving I was reminded how scary public computers are and why you should avoid them.  Publicly available computers are popping everywhere and increasingly ubiquitous with our daily lives.  A few of the computers I ran into this weekend include: while waiting for an oil change at Mobile 1, a café for breakfast and the hotel I stayed at.

Public computers can be security nightmares

This weekend I intentionally left my laptop behind (a difficult separation for me) so I wouldn’t be “distracted”.  That didn’t help.  At the hot springs resort I stayed, I was drawn to a computer in the common room.  The system was a disaster and not something you should enter any personal information through.  I gave the system a very quick look over and found multiple problems.  The problems include: the anti-virus product was out of date (which means it is not receiving new detection files and will miss all new threats), the browser had two rogue toolbars capable of scraping off your search results and sending them to unintended web servers, the operating system was not up to date and vulnerable to (additional) infections, and there were a variety of suspicious processes running I could not analyze on site (they appeared to be trojans).  The system also contained an enormous amount of personal information from previous users, like login credentials for Facebook and webmail accounts (I saved these people some embarrassment and gave the system a scrubbing after I was done investigating).

Also, the system allowed everyone to login as administrator.  I didn’t have time to fully inspect the computer, but it, like all publicly accessible computers, could easily have contained keylogger software.  Keylogger software is readily available and very powerful (learn more:  It is named “keylogger” because it allows the attacker (the person who installed it) to log all keystrokes entered and websites visited and forward this information to the remote attacker.  Once installed, the software can run quietly in the background capturing passwords, bank logins, etc.  It is scary how easy this can be done.

The computer I used at the café was in better shape – showing no sign of malware infection.  It was running shared access software.  No strange toolbars or suspicious processes running, but still, not something I would enter personal information into.

Here are a few tips on how to use a public computer safely:

  • Tip 1: Avoid entering personal information.  In general, avoid using a public computer for online banking, logging into your webmail account, logging into blogs, social networking sites, filling out online forms or any other site that asks for personal information..
  • Tip 2: Do not save login information.  Login information can be stored by the Windows operating system, websites and through other means.  When using a public computer, avoid storing this information by clicking ‘do not save’.  In addition, whenever you login into a site, be sure to formally logout using the “logout” button provided.
  • Tip 3: Delete browser history (more information here), cookies (more information here), and temporary internet files (more information here).  Before you logoff the computer, use the browser to delete this information.
  • Tip 4: Be aware who is around you.  I am not encouraging paranoia, but just like when you use an ATM, be aware of anyone around you that might be able to note the information you are entering.
  • Tip 5: Check for shared access software.  Shared access software is designed to give each user of a public computer a clean system without spyware and viruses, block users from installing programs, and erase you personal information once you logoff.  This software helps keep your personal data private and future computer users from having access to it.  For example, Windows offers SteadyState for free

Look for windows like this when you log in and while logged in:

and this

  • Tip 6: Do you trust the owner?  Again, not to sound too paranoid, but the security of public computer you are using is good only to the extent you trust the administrator of it.  Anyone with administrator rights can install a keylogger that runs in the background and harvest every bit of personal information you enter.
  • Tip 7: Avoid shopping online.  Shopping online either requires you enter your credit card or log into a website you previously signed up for (and stored credit card information).


Stay away from typing or otherwise entering personal information while using publicly available computers – like those found in coffee shops, libraries, and other locations.  Be particularly cautious of computers that do not require you to login as a guest user and do not have shared access software installed – assuring your personal data will be deleted once you logoff.  Unrestricted, public computers are dangerous and are often riddled with spyware (whether it is apparent to you or not).  Feel free to use public computers for non-critical computing like reading the news, checking the weather or looking at stocks, but if prompted for any type of personal information, the red flags should go up and caution should be exercised.

By: Benjamin Googins


Benjamin Googins is a senior engineer working on CA’s Anti-Spyware product. His primary functions include analyzing spyware and privacy breaches, fielding press inquiries, blogging and drafting documents. He has been a significant contributor to the User Permission document , Spyware Scorecard , Threat… Read More..

1 person has left a comment:


Posted by: Milo Wilson, December 19, 2008 10:43 PM

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