Online tools

Useful freeware and other online tools.
A more detailed list of freeware may be found at: gizmo's freeware such as this article, Probably the Best Free Security List in the World

Free online single file scanning

• http://virustotal.com (max file size 20 MB, 42 different antiviruses)
• http://virscan.org (max file size 20 MB, 37 different antiviruses)
• http://scanner.novirusthanks.org (max file size 20 MB, 24 different antiviruses)
• http://scanner.virus.org (max file size 5 MB, 23 different antiviruses)
• http://virusscan.jotti.org (max file size 10 MB, 20 different antiviruses)
• http://viruschief.com (10 different antiviruses)
• http://filterbit.com (9 different antiviruses)

Free online folder/computer scanning

• a-squared : http://www.emsisoft.com/en/software/ax/?scan=1
• BitDefender : http://www.bitdefender.com/scanner/online/free.html
• Computer Associates : http://cainternetsecurity.net/entscanner/
• ESET (NOD32) : http://www.eset.com/onlinescan/
• F-Secure: http://www.f-secure.com/en_EMEA/security/security-lab/tools-and-services/online-scanner/index.html (IE only)
• Microsoft OneCare : http://onecare.live.com/site/en-us/default.htm
• TrendMicro : http://housecall.trendmicro.com
• Panda : http://www.pandasecurity.com/activescan/index/

Anti-Virus / Anti-Malware products free and fully functional

Anti-virus

• avast! : http://www.avast.com/
• AntiVir : http://www.avira.com/
  alternate: http://free-av.com/
  AntiVir Free update problem
• AVG : http://www.avg.com/
• Comodo : http://www.comodo.com/
• ClamWin : http://www.clamwin.com/
• ClamAV : http://www.clamav.net/
• Microsoft Security Essentials : https://www.microsoft.com/Security_essentials/
• Panda Cloud : http://www.cloudantivirus.com/

Anti-Malware

• Ad-Aware : http://www.lavasoft.com
• a-squared : https://www.emsisoft.com
• MalwareBytes : http://www.malwarebytes.org
• Spybot S&D : http://www.safer-networking.org/index2.html

Anti-spyware products

• SpywareBlaster : https://www.javacoolsoftware.com
• Spyware Terminator : https://www.spywareterminator.com
• SUPERAntiSpyware : https://www.superantispyware.com
• Windows Defender : https://www.microsoft.com/windows/products/winfamily/defender/default.mspx

Intrusion prevention

• GeSWall : http://www.gentlesecurity.com

Windows start-up manager

• WinPatrol : http://winpatrol.com

Windows system scanner

• HijackThis (HJT) : http://free.antivirus.com/hijackthis/
  (used in conjunction with Malware support forums for troubleshooting system failures)

MX tools

Check if your IP or domain is blacklisted as a source for Spam

• http://www.mxtoolbox.com/ : Check each MX record (IP Address) against 147 DNS based blacklists.

Spam / PHISH aggregators

• AbuseButler : http://spamvertised.abusebutler.com
• joewein.de LLC : http://www.joewein.net
• PhishTank : http://www.phishtank.com
• Project Honey Pot : https://www.projecthoneypot.org
• SORBS (Spam and Open-Relay Blocking System) : http://www.us.sorbs.net
• Spacequad : http://www.spacequad.com
• SpamCop : http://www.spamcop.net
• SURBL : http://www.surbl.org
• uriBL : http://www.uribl.com

Reputation tools

These tools can help evaluate the reputation of websites. Some are based on user reports, corporate/organization reports or automated tools (links checkers, anti-viruses, sandboxes...)

• ATMA IP Deny list - Peerguardian format : http://www.atma.es
• AVG LinkScanner : http://linkscanner.explabs.com/linkscanner/avg
• Browser Defender : http://www.browserdefender.com
• Google Safe Browsing : http://www.google.com/safebrowsing/diagnostic?site=example.com (replace "example.com" with the IP or domain name)
• hpHosts : http://hosts-file.net
• MalwareDomainList : http://www.malwaredomainlist.com/mdl.php
• MalwarePatrol : http://www.malwarepatrol.net/lists.shtml
• MalwareUrl : http://www.malwareurl.com
• McAfee SiteAdvisor : https://www.siteadvisor.com
• McAfee TrustedSource : https://www.trustedsource.org/en/tools
• No Virus, Thanks : http://scanner.novirusthanks.org (File Scanning)
• Norton SafeWeb : https://safeweb.norton.com
• Phish Tank : http://www.phishtank.com
• Unmask Parasites : http://unmaskparasites.com
• URL Void : http://www.urlvoid.com
• Web Security Guard : http://www.websecurityguard.com
• Sitevet : http://sitevet.com/

Network tools

• http://www.aguse.jp/ : whois, DNS, thumbnail, blacklist check, more.
• http://centralops.net/co/ : Free online network utilities
• http://clez.net/net/ : Free complete network tools for online research.
• http://whois.domaintools.com/ : Whois lookup and Domain name search.
• http://www.who.is/ : whois, DNS, more.
• http://ping.eu : online ping/whois/traceroute/port check/reverse lookup/...
• http://www.geoiptool.com/ : Free online geolocation (from server name or IP)
• http://ipinfodb.com/ : Free online geolocation (from server name or IP)
• http://www.robtex.com/ : Swiss army knife internet tool. Check: RBL, DNS, IP, C-net, whois, Route, AS info, and more.
• http://www.intodns.com/ : checks the health and configuration and provides DNS report and mail servers report.
• http://network-tools.com/ : various: ping, whois, DNS, etc.
• http://untiny.me/ : Get real url from shortened URLs like tinyurl.com (and other) without actually following the link
• http://www.just-traceroute.com/ : Traceroute from 4 different locations.
• http://www.herdict.org/web/ : Herdict Web aggregates reports of inaccessible sites

Pharmacy verification

• http://www.nabp.net : The National Association of Boards of Pharmacy
• http://www.ciparx.ca : The Canadian International Pharmacy Association
• http://www.legitscript.com : LegitScript (USA and Canada)

SSL Certification testing

• https://www.digicert.com/help : Check SSL Certificate for proper installation.
• https://www.sslshopper.com/ssl-checker.html : Check SSL Certificate, also has a widget to add to your website or blog.

Parental control

See main article: Parental Controls

List of Noteworthy Internet Explorer addons

• Simple Adblock : http://simple-adblock.com
• heise SSL Guardian : http://www.h-online.com/security/features/Heise-SSL-Guardian-746213.html
• IE7Pro : http://www.ie7pro.com
• KeyScrambler : https://www.qfxsoftware.com/Download.htm

Find more at http://www.ieaddons.com/en/

List of Noteworthy Firefox addons

See main article: Firefox

Check for obsolete software

Scans for outdated software that is vulnerable to exploit codes, etc.

• F-Secure : http://support.f-secure.com/enu/home/onlineservices/fshc.shtml
• Secunia OSI : http://secunia.com/vulnerability_scanning/online/
• FileHippo.com Update Checker : http://www.filehippo.com/updatechecker/
• Plug-In Check for Firefox : https://www-trunk.stage.mozilla.com/en-US/plugincheck/

Miscellaneous

• Anubis : http://anubis.iseclab.org/ (reports the behavior of a Windows executable and activities in Internet Explorer)
• AutoShun (snort list) : http://www.autoshun.org/
• Better Business Bureau (USA and Canada company verification) : https://www.bbb.org
• Bitzi : http://bitzi.com/ (Collaborative file identification)
• BoardReader domain link check : http://boardreader.com/domain/mywot.com
• Malicious code detection (PDF/Javascript/Flash): http://wepawet.iseclab.org/
• Newly Registered Domain Names : http://domain-daily.com/
• NetworkMiner (Network Forensic Analysis Tool (NFAT) for Windows) : http://networkminer.sourceforge.net/
• Norman Sandbox : http://www.norman.com/microsites/nsic/Submit/en (reports the behaviour of a Windows executable run inside a virtual machine).
• PC Flank Security Tests : http://www.pcflank.com/index.htm (scans for possible exploits you are leaving behind you)
• Pop-up Test : http://www.popuptest.com/ (tests your pop-up blocker)
• Sandboxie : http://www.sandboxie.com/ (reports the behaviour of a Windows executable run inside a sandbox)
• Site Dossier : http://sitedossier.com/
• Snort network intrusion prevention and detection system (IDS/IPS) : http://www.snort.org/
• Spamavert.com : http://spamavert.com/ (obtain spam from this small inbox)
• SystemLookup : http://www.systemlookup.com/ (search engine for CLSIDs, services and etc. listing them as either legitimate or malicious)
• Tor : http://www.torproject.org/ (surf with more privacy)
• VB100% : http://www.virusbtn.com/vb100/index (keep updated on which antiviruses are passing the latest malware tests)
• WebCHeck (UK company verification) : http://wck2.companieshouse.gov.uk/53444b46005755607d6d6b965d400416/wcframe?name=accessCompanyInfo