Software that searches for known viruses. Also known as a "virus scanner." As new viruses are discovered by the antivirus vendor, their binary patterns are added to a signature database that is downloaded periodically to the user's antivirus program via the Web. See virus, quarantine, disinfect and behavior blocking.
Two Different Approaches
Virus scanners work two ways. The more common method scans the file against all known viruses each time the file is opened. The second method, such as used by the Sophos antivirus program, takes a blueprint of every file ahead of time. It computes a checksum of each file's contents and stores it in a database. The next time a file is opened, the software recomputes the checksum and compares it to the one in the database to see if the file has changed. If it has, the program scans the file for viruses. If not, the file is considered virus free. Since most files are virus free, this method is faster because recomputing a checksum is considerably faster than comparing the file with all the binary signatures. See Sophos and checksum.
Two Different Approaches
Virus scanners work two ways. The more common method scans the file against all known viruses each time the file is opened. The second method, such as used by the Sophos antivirus program, takes a blueprint of every file ahead of time. It computes a checksum of each file's contents and stores it in a database. The next time a file is opened, the software recomputes the checksum and compares it to the one in the database to see if the file has changed. If it has, the program scans the file for viruses. If not, the file is considered virus free. Since most files are virus free, this method is faster because recomputing a checksum is considerably faster than comparing the file with all the binary signatures. See Sophos and checksum.
 | Reproduced with permission from Computer Desktop Encyclopedia. Copyright (c) 1981-2009 The Computer Language Company Inc. All rights reserved. |
Additional Resources
- My scareware night and how McAfee lost a customer
- With their Comcast and AT&T dealsMcAfee has a huge market share hereit pretty much does nothing to prevent being infected by these rogue antivirus attacks.I have found Combofix (http://www.bleepingcomputer.com/combofix/how-to-use-combofix)is the most effective tool to remove these things but even that isn't 100%.Usually you will want to rename it before you...
- Discussion threads 2009-11-12
- 10 antivirus programs for Windows 7
- Windows 7 offers some new security features, but a good antivirus program can provide additional protection. Greg Shultz put together a list of 10 solid Windows 7-compatible choices.This download is also available as an entry in our 10 Things blog.
- Download resources 2009-11-11
- Panda Cloud Antivirus leaves beta
- Panda Cloud Antivirus is notable as a free security solution for two reasons: Panda is a reputable security vendor, and the program achieves its goal of freeing up system resources. by CNET News.com
- Image galleries 2009-11-10
- Which antivirus is best at removing malware?
- Run a Linux distro or a MacIt is funny, when you 'weld' a web_browserinto an operating system and viruses/worms/malware/trojans and spyware come in from outside sources it is amazing how insecureit makes an Operating System.Say what you will, Linux distro's power theInternet with Bind dns, dhcp, routers/switchesand they do not...
- Discussion threads 2009-11-05
- ZoneAlarm Anti-virus 2010 9.1.008 (Windows)
- ZoneAlarm Antivirus includes browser security features such as Advanced Download Protection; Detects the latest zero-day threats in downloads that you initiate--before they reach your computer, and heuristic analysis and program check. Additional layer of keylogger protection--encryption ensures only the intended application can read your keystrokes.
- Software downloads 2009-11-05
- SoftControl Antivirus 1.0.0.1 (Windows)
- SoftControl AntiVirus and System Analyzer. A Program to scan and eliminate Malwares/Viruses/Rootkits upon found. Very fast file scan by utilizing Clamav GPL scan engine. Realtime scan to detect new threats. Includes a registry scanning and analyzing utility. Consumes very low cpu usage. Help for usages can be found during program...
- Software downloads 2009-10-30
- AVG Anti-Virus Network Edition 9.0.700 (Windows)
- Centrally controlled security protection against viruses, worms, trojans and potentially unwanted programs combined with desktop firewall protection against intrusions and hacking.Includes: Anti-Virus protects from viruses, worms and trojans; Firewall provides individual security against hackers; Central administration of all features, including desktop firewall, updates, and scheduling. Features: Reduces administrator workload and...
- Software downloads 2009-10-27
- AVG Email Server Edition 9.0.700 (Windows)
- Security protection against viruses, worms, trojans, spyware and adware for even the most demanding e-mail servers. Includes:Anti-Virus protects from viruses, worms and trojans,Anti-Spyware protects from spyware, adware and other malicious programs,Remote administration of all features (except additional plug-ins). Features: Reduces administrator workload and maximize the security of your e-mail...
- Software downloads 2009-10-27
- Kingsoft Internet Security 9 Plus 2009.04.14.59 (Windows)
- Kingsoft Internet Security 9 Plus includes anti-virus, anti-malware, a vulnerability scanner and personal firewall. Find and fix rootkits, spyware, trojans, virus and malware infections. The webshield protects you from infection while surfing the Internet. The suite also includes many other useful tools: usb flash rescue disk creation, history cleaner, disk...
- Software downloads 2009-10-25
- Rogue security programs are 'ongoing threat'
- The sites of these 'rogue security programs'Should be immediately shut down when they are found, by doing a DDoS attack if necessary.There is no reason to allow these bastards to shill their break-ware on the rest of us in the world.Getting worse...I've seen a hugh increase in infections from these...
- Discussion threads 2009-10-20
- The Shield Deluxe 2010 13.0.16 (Windows)
- The Shield Deluxe 2010 combines reactive antivirus and spyware detection methods with the latest proactive technologies to provide your computer with the most effective protection against malicious programs. The product is simple to install and set up, while offering advanced users a range of versatile settings for fine-tuning the program....
- Software downloads 2009-10-20
- Windows 7 in action: a closer look at Windows XP Mode
- Now that's coolSo XP apps can be run directly on the desktop? Now that's cool :).How is this different than Virtual PC?Ed, I have XP running under MS Virtual PC 2007 on my Vista Business x64 machine. How is this different? I know that I had to supply...
- Discussion threads 2009-10-19
- Fake 'Conficker.B Infection Alert' spam campaign drops scareware
- An ongoing spam campaign is once again attempting to impersonate Microsoft's security team -- the same campaign was first seen in April -- by mass mailing Conficker.B Infection Alerts (install.zip), which upon execution drop a sample of the Antivirus Pro 2010 scareware. Whereas the theme remains the...
- Blog posts 2009-10-19
- Anti-Virus Descargar 1.5 (Windows)
- Anti-virus Descargar offers comprehensive protection against viruses, worms, Trojans and dialers. It checks and protects all the relevant system areas of your computer. This application detects over 20,000 viruses variants and also offers full scan memory active processes. Anti-virus Descargar used to detect and remove major viruses. It is not...
- Software downloads 2009-10-12
- Zone Alarm Extreme Security 2010
- Best known for its ZoneAlarm firewall, Check Point Software also publishes two full-featured security suites. ZoneAlarm Internet Security 2010 gives users a robust firewall, antivirus and antispyware, and parental control package for $49.95, while ZoneAlarm Extreme Security 2010 adds Web browsing protection, system tune-up tools, backup options, and anti-phishing technology...
- Product reviews 2009-10-08
- Study: Windows 7 can boot more slowly than Vista
- Windows Boot UpWell you know I think that the average user understand the boot up scenario.the more crap you add to your PC the longer it will take to become usable.All of those little dormant services being energized.Hell a clean install of Windows 7 on a Dell 530s with 4...
- Discussion threads 2009-10-08
- AVG Free 8.0 Anti-Virus Definitions 2009-09-20 (Windows)
- In order to provide the highest level of antivirus protection for users of AVG Free, AVG Technologies continuously develops information about new viruses. This information, as well as product improvements, is provided to the users of AVG Free in the form of Updates. Timely virus database updates are the critical...
- Software downloads 2009-10-07
- UserGate Proxy & Firewall 5.2 (Windows)
- UserGate is a complex solution for sharing Internet access among employees in your company, making traffic calculations, and protecting your local network against malicious activity and software, such as hacker attacks, viruses and Trojans. UserGate is a flexible yet very powerful program that can be used in small- and mid-sized...
- Software downloads 2009-10-06
- AutoClickExtreme 5.02 (Windows)
- AutoClickExtreme is ShareWare. After 41 days of using the program, you'll have access only to the simple view. When you register the program, all limitations will be taken away. AutoClickExtreme is, in essence, a keylogger, so many antivirus programs will warn you about it. (A keylogger is a program which...
- Software downloads 2009-10-05
- MS Security Essentials test shows 98% detection rate for 545k malware samples
- According to recent tests conducted by AV-Test.org aiming to measure the performance of Microsoft's Security Essentials, the freeware application achieved 98% detection rate for 545k malware samples including viruses, bots, trojan horses, backdoors and Internet worms, also achieving 90.95% detection rate for 14,222 adware/spyware samples it was tested against. ...
- Blog posts 2009-10-01
Neighboring Terms
Premier Vendor Content Whitepapers, webcasts & resources from our Power Center Sponsors
- The more you simplify, the more you save
-
When you transition from your existing Red Hat environment to SUSE Linux Enterprise from Novell, you can recognize dramatic cost savings, perhaps as much 50%
- Learn more >>
- Save time with automated shipping solutions
-
The Business Essentials Guide provides you useful tools and templates to help grow your business and save you time with automated shipping solutions.
- Visit the UPS Business Essentials Guide
- The best support in the Linux business
-
If Linux is going to power your mission-critical applications, you'd better have the best support known to business. Novell was rated the top provider of Linux technical support.
- Learn more >>
- The best support in the Linux business
-
If Linux is going to power your mission-critical applications, you'd better have the best support known to business. Novell was rated the top provider of Linux technical support.
- Learn more >>
SmartPlanet
- Thought-provoking progressive ideas on diverse topics that intersect with technology, business, and life, and matter to the world at large. Visit SmartPlanet
- More from IBM
-
- Can your business work smarter? Learn more about Lotus Symphony
- Learn how to work smarter and optimize cost using the IBM Smart SOA approach Download the eBook
- Smarter ways to make smarter products Read the brief from IBM
