How Security Threats Affect PC Performance

By | April 16, 2006

Security threats are everywhere – spyware and adware installed inadvertently over the internet, viruses transmitted through email, keyloggers penetrating your firewall, malicious code broadcast over peer-to-peer networks. Here are five threats that will reduce system performance, destabilise your system, generate unusual behaviour, modify your Windows Registry and hog your Internet bandwidth.

Security threats are everywhere: The Sources – software downloads, peer-to-peer networks (e.g., Kazaa), floppies, CD or DVDs, emails and their attachments, chat rooms, your colleagues on the network and the Internet in general. The Threats – spyware and adware installed inadvertently over the internet, viruses transmitted through email, keyloggers penetrating your firewall, malicious code broadcast over peer-to-peer networks.

Aside from the threat to the safety of your data, malware can have serious effects on your system and resource performance. Even your internet connection and network bandwidth can be at risk. Here are some examples of malware that effect system performance and how they do it.

What´s Malware?

According to Virus Bulletin: “Malware (short for malicious software) comes in a vast array of different forms, each of which is designed specifically to damage or disrupt the infected machine or other networked machines.

From redirecting your search attempts, to serving up pop-up ads, tracking the websites you visit, or deleting your important documents, malware can sit quietly on your computer without you ever even noticing, or it can slow down, disrupt or even periodically reboot your system.

It will often to hide deep inside your system making removing it all the more difficult and may even reinstall itself even after you thought you had deleted it!”

The popular view is that malware either compromise or destroy your data (e.g., wipe your hard drives clean) or steal information about you and send it to third parties for not so legitimate reasons.

This is not entirely true. Yes, these are common effects but some malware does effect system performance hogging resources and drastically slowing your PC down. The following examples, taken from the authoritative Virus Bulletin, are a few examples of malware and their effects on your system:

Malware Degrades System Performance

W/32 Funlove infects files with .exe., .scr, .ocx extensions and spreads through a variety of methods. The virus, according to Symantec, resides in memory and will reinfect files thus exhibiting great resilience. The virus adds data to files making them larger and larger. Other side effects include – system instablility, poorer system performance, and unusual behaviour.

Malware Renders system unstable

W32/Blaster is a worm that takes advantage of a vulnerability in Windows (2000, XP, NT and Server 2003) and causes unexpected system error messages and automatic reboots. There are several variants to this worm and side effects also include registry modification and unusual behaviour. One variant, W32/Blaster.a actually scans for vulnerable computers connected to the Internet.

In 2003, Microsoft marked this worm as a critical security threat.

(Registry modification is very dangerous as it may effect the overall smooth operation of your PC even causing an inability to start Windows. For more details read What is the Windows Registry? and The Structure of the Windows Registry).

Malware Generates unusual system behavior

In January 2004 W32/Mydoom was recorded as “the worst e-mail worm incident in virus history” by F-Secure – it propagates itself through email and over the Kazaa file-sharing network. The main effects include denial of service attacks, unusual behaviour, modification of system registry and may grant remote access to your computer.

Malware Modifies the system registry

Very difficult to detect, W32/Lovgate is another worm that spreads through email. It is also transmitted over network shares while trying to open up remote connections to computers through backdoors. According to ZD Net the virus “opens up port 10168. Ports are the software addresses used by applications running on one computer to communicate with other applications running on other systems across a network. By knowing the Internet address of the victim´s computer, the port number and the password used by the Trojan horse, an intruder can take control of an infected PC.”

Malware Downloads code from the Internet

W32/Sobig is an worm that spreads through email. According to ZD Net, by mid January 2003 this virus was the second most common virus in the Internet. The worm has its own SMTP engine that allows it to send emails in its own right to propagate itself on other machines. When activated the worm downloads a list of web addresses to which it then connects to download a program and subsequently run it on the infected machine. In a LAN environment, Sobig will also try to copy itself onto shared folders.

So, do you think it pays you not to protect your system?

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