An almost overwhelming sea of malicious software suffuses cyberspace.  Thousands and thousands of hackers around the world dedicate vast quantities of time to developing ever more dangerous and insidious computer infections.  In the early days of the Internet, computer viruses were most users' main concern.  Experts warned everyone not to download suspicious attachments and not to insert random, unidentified disks into their computers.  That advice is still sound, but nowadays traditional computer viruses account for only a tiny percentage of the infections that strike typical computer users.

Today, malware (portmandeau for malicious software) is much more common than viruses.  Though many people still refer to malware as viruses (including computer technicians!), there are several different categories of threats:

• Traditional computer viruses: These infections typically require user action to infect a computer.  A user needs to download an attachment or run a compromised program to become infected.  The virus then tries to spread itself by sending itself to other computers, either across a local network or via e-mail in most cases.
• Rootkits: This threat, usually quite dangerous and difficult to remove, often hijacks legitimate Windows system drivers that load before Windows even finishes booting.  As such, they are often invisible to Windows and many security products.  They can cause computers to slow down and crash, and they often redirect search engine results (i.e. clicking on a Google result leads users to an unfamiliar, random page, usually full of spam).  Many of them also attempt to steal financial information and are used in cyber indentity theft schemes.  Rootkits can be "caught" by visiting a website that has been infected or hijacked and are often transmitted through advertisements and torrents.
• Fraudware or Scareware: Fake anti-virus products that paralyze a computer system, deny Internet access, and/or attempt to extort money from unsuspecting computer users fall into this category.  This malware sometimes tricks users into installing it, but it can also sometimes be transmitted through compromised websites.
• Keyloggers: This malware logs every single key stroke on your computer.  Keyloggers can be extremely difficult to detect and will often upload information dumps to a foreign FTP server where text is sifted for valuable usernames, passwords, credit card numbers, etc.  Keyloggers are sometimes stealthily downloaded and installed on computers compromised by rootkits.  They can also be installed by actual people with physical or remote access to a computer.
• Bootkits: Similar to rootkits, bootkits (also known as boot sector viruses) actually bypass Windows altogether and reside on a tiny part of a computer's hard drive outside of Windows.  Well-designed bootkits can accomplish nearly anything and will often join computers to vast "botnets" that expert hackers use in massive cyber attacks, spamming ventures, and other criminal activities.

• Spyware/Adware: These types of threats are the lowest risk level.  They typically track consumer behavior and serve unwanted advertisements to Internet users.  They can significantly slow down a computer by using large amounts of memory and CPU resources.

Standard antivirus products will protect against most traditional computer viruses and most adware and spyware infections but are particularly susceptible to newly engineered or modified rootkits and bootkits.  Popular scanning and removal tools, such as SpyBot or SUPERAntiSpyware will remove many minor infections but are often not particularly useful against many these deep level infections.  Many users also may not even be aware that they are infected.  In fact, the TDL-4 botnet actually seeks out and destroys any other potential malware on a user's computer and does its best to remain unnoticed.  Security researchers estimate that as of June 2011 4.5 million computers were actively infected with TDL-4 (Daily Tech Story).

Computer users should be concerned about the state of their computer if any of the following are true:

• The computer has inexplicably and suddenly slowed down.
• Random blue screen errors appear without symptoms such as overheating, clicking hard drives, noisy fans, etc.
• Websites and Internet-based downloads, songs, videos, etc. are loading more slowly than normal over a consistent period of time
• Clicking on search engine result links don't lead to where they should (even if only every once in a while).
• Random programs suddenly stop working or start working differently.
• Inexplicable visual or user interface changes appear.

If you think your computer may be infected, we recommend that you have an expert friend, co-worker, or professional examine your computer.  Even though PC Experts itself provides remote support services, we absolutely recommend against doing any over-the-Internet remote security scans.  The scans themselves are unreliable, and many of the companies that provide these services do so without guarantees and with a surprisingly poor track record. Please feel free to use our free This e-mail address is being protected from spambots. You need JavaScript enabled to view it service if you have any questions.  If you are in the Austin area and feel like you need in-person assistance, please remember that we are there for all of your local Austin computer repair and laptop repair needs.