E-Threats Tips and Tricks

Infected or Not? Five Symptoms of a Security Breach

Most viruses, worms and Trojans circulating nowadays have learned to be discreet to avoid detection. Unlike predecessors that displayed warnings on users’ monitors, modern malware operates silently because crooks understood that users will install an antivirus to clean their computer at the first sign of infection.

But, no matter how stealthy these pieces of malware are, there are still signs that give them away. Here’s a list of five such signs that can help you determine whether your PC is infected:

  • Increased CPU activity. Some malware performs CPU-intensive tasks (such as mining for Bitcoins, or brute-forcing passwords). Before jumping to conclusions, though, check if the CPU spike is caused by a legit application, such as video editing software or compression utilities.
  • Keep an eye on the bandwidth. Worms and Trojans exchange lots of data with their command and control servers or, even worse, send spam or specially crafted data packets to trigger denial of service attacks. If your Internet connection is sluggish, close all applications that legitimately transfer large amounts of data across the web (such as file sharing utilities or other Internet downloads) and see if the network usage drops. If not, you’re probably infected. 
  • Unknown files keep showing up in your boot partition. Malware usually creates temporary files or writes configuration details in the boot partition. If you see files that look suspicious, look them up on the web to check if they belong to a known application. If they are there and – most importantly – if they get re-created after you have deleted them once, run an online scan to see if you are infected. 
  • You keep sending messages to your contacts. Some infected computers automatically send shady messages to contact lists via IM or e-mail. If you notice your system does this, disconnect your PC from the network and run an antivirus scan to identify the infection. 
  • Lots of alerts about your PC security shown on your desktop. This is by far the most obvious hint as to your PC’s poor security. If you happen to get plenty of alerts from an antivirus you have never heard of that you are infected, it’s clear that you’re infected with a Rogue AV. Installing an antivirus is the only way to clean the infection, as these rogue products rarely come alone.

Bottom line: Most malware tries to stay undetected as long as possible to take advantage of your infected PC. You should perform regular scans with either an online scanner or with a regular antivirus utility. Don’t wait until cops show up at your door with a warrant. Act responsibly and protect your PC to keep your virtual friends safe.

About the author


A blend of teacher and technical journalist with a pinch of e-threat analysis, Loredana Botezatu writes mostly about malware and spam. She believes that most errors happen between the keyboard and the chair. Loredana has been writing about the IT world and e-security for well over five years and has made a personal goal out of educating computer users about the ins and outs of the cybercrime ecosystem.