Antivirus Scanner
Leida Gamage
If the virus scanner is either unavailable for any reason or has timed out, it poses a risk for users who are accessing potentially infected documents. Therefore, users are advised to contact the SharePoint administrator so that corrective action can be taken to resolve the problem and virus scanning of documents can continue.
Microsoft is aware of this behavior. In investigating this issue, it was determined that making a change to the design of the product to differentiate a real virus infection from a scanner time-out would involve a significant design and testing effort that requires careful planning and execution.
I see lots of people claim virus scanners are unnecessary on a linux server. But if this server accepts files uploaded from users (and lets others download them), does it become worth it to scan the files when they are uploaded on the server?
Virus scanners for Linux look for Windows viruses. The logic is that your Linux server is acting as a file-storage location for users who are running Windows, and therefore scanning for Windows viruses will help protect your users.
So, for example, a vulnerable Wordpress plugin on Linux is vaguely analogous to a vulnerable Microsoft Office installation on Windows. On the Windows desktop, you carefully examine all inbound Microsoft Office documents, checking to see if any will exploit the vulnerability in Office. But on the Linux server, you just remove or patch your Wordpress plugin and be done with it. Instead of keeping an antivirus up-to-date, you're supposed to keep your server up-to-date.
A WAF is built on the idea of protecting vulnerable sites from exploit much the same way as an antivirus tries to protect vulnerable desktops. It even uses roughly the same technique (looking for and blocking certain patterns). But while all antivirus products err heavily on the side of avoiding false-positives, a WAF can be configured to be so permissive as to be useless, or so restrictive as to break your site.
In theory, a virus scanner on the users machine would be enough, but why trust that hundreds or even thousands of computers have their virus scanners up-to-date, actually running (some people might have admin rights and disable the virus scanner e.g. when they are developing internal apps and need to not mess with the debugger)? And who knows where else that file is now? If you can already scan the file at the moment it comes in and only release it then, why not?
Could anyone please give me instructions how to install free Bitdefender antivirus (with a Personal License key obtained via mail) from terminal in Ubuntu 16.04? (The case of installing "bitdefender non-free" doesn't fit.)...I am trying to install the product named "Bitdefender Antivirus Scanner for Unices" of which I have been given yesterday Aug.17,2016 via email a free Personal License key (for personal use only), after having contacted -for-unices.htmland requesting a Free Licence.I have downloaded 3 possible suitable installation files and tried (in vain!) to run the first and appearing most applicable one to my system of AMD-64bits-PC with Ubuntu 16.04 LTS:
The tricky thing about antivirus software is that it seems like a fairly mysterious piece of software. How does it work nowadays? What is it meant to do and what is outside its purview? Every company has their own secret sauce that makes their technology just a little bit different from everyone else, so it gets increasingly difficult to say what makes antivirus go.
So it makes sense for anti-virus scanners to look for common properties of those popular malware families or known malicious behavior if they want to be have any hope of keeping up. These generic detections can be fairly broad or fairly specific. For example, it could scan for known exploit code that could be added to known malware or brand-new creations. Or it could look for specific packers that are used by only one malware family.
Some clients have antivirus software that scans the same temporary directory (it simply scans everything). We tried to talk them into disabling it - it doesn't work, so it's out of the question either.
Every once in a while (something like once for every one thousand file operations) my application tries to perform an operation on a file which is at that very time opened by the antivirus and is therefore locked by the operating system. A sharing violation occurs and causes an error in my application. This happens about once in three minutes on average.
Okay, enough ranting. If a file is locked by some other process then you can use a "try again" strategy like you suggest. OTOH, do you really need to close and then re-open those files? Can't you keep them open until your process is done?One tip: Add a delay (sleep) when you try to re-open the file again. About 100 ms should be enough. If the virusscanner keeps the file open that long then it's a real bad scanner. Clients with scanners that bad deserve the exception message that they'll see.Typically, try up to three times... -> Open, on failure try again, on second failure try again, on third failure just crash.
I noticed an oddity with some of the websites I built. I have one, that has been HTTP since 10 years. A few years ago when changing hosting, I accidentally activated SSL on it, but cancelled the SSL right away (I cannot run that site engine on HTTPS). The site is up and running, but sometimes when I visit it since then, I get an error message: "Your connection is not private" from the browser or a similar error message from the virus scanner. I noticed this happens when I empty the cache of the browser, and type "mydomain.com" only to the search bar. If I type " ", the site loads fine. So it seems the problem is that the browser is trying to force HTTPS even if the certificate has been cancelled long ago. Recently I did the same mistake with another site, when moving to another hosting, accidentally ticked the SSL option, and even if I cancelled it later, now the same error is happening there too. I checked the error message carefully, and noticed an oddity. For the other site, where I cancelled the SSL years ago, the Virus scanner error message still displays the certificate as if it was valid. Check the photo attached. But it is not valid any more. It has been cancelled long ago, and my hosting provider confirmed it makes no effect. Yet, Kaspersky and Eset scanners are looking for it and report it as valid. How is this possible?
For a while I thought this is a universal problem, but today I investigated that this error is only present on my own computers. That is: on computers where I visited the problem sites during the time when the SSLs were active. So I came to the conclusion now that something was saved on my computers that makes the Virus scanners still look for the certificates and consider the website HTTPS.
Does anyone know why this is? Maybe Windows stores SSL certificates in the Certificate Inventory, and if the certificate of a site has problems, the Virus Scanner flags it as risky? Or it is the virus scanner itself that stores previous SSL info somewhere and is checking it against the recent state of the site to determine risk?
Antivirus software was originally developed to detect and remove computer viruses, hence the name. However, with the proliferation of other malware, antivirus software started to protect against other computer threats. Some products also include protection from malicious URLs, spam, and phishing.[1]
There are competing claims for the innovator of the first antivirus product. Possibly, the first publicly documented removal of an "in the wild" computer virus (i.e. the "Vienna virus") was performed by Bernd Fix in 1987.[19][20]
In 1987, Andreas Lüning and Kai Figge, who founded G Data Software in 1985, released their first antivirus product for the Atari ST platform.[21] In 1987, the Ultimate Virus Killer (UVK) was also released.[22] This was the de facto industry standard virus killer for the Atari ST and Atari Falcon, the last version of which (version 9.0) was released in April 2004.[citation needed] In 1987, in the United States, John McAfee founded the McAfee company (was part of Intel Security[23]) and, at the end of that year, he released the first version of VirusScan.[24] Also in 1987 (in Czechoslovakia), Peter Paško, Rudolf Hrubý, and Miroslav Trnka created the first version of NOD antivirus.[25][26]
Finally, at the end of 1987, the first two heuristic antivirus utilities were released: Flushot Plus by Ross Greenberg[28][29][30] and Anti4us by Erwin Lanting.[31] In his O'Reilly book, Malicious Mobile Code: Virus Protection for Windows, Roger Grimes described Flushot Plus as "the first holistic program to fight malicious mobile code (MMC)."[32]
In 1989, in Iceland, Friðrik Skúlason created the first version of F-PROT Anti-Virus (he founded FRISK Software only in 1993). Meanwhile, in the United States, Symantec (founded by Gary Hendrix in 1982) launched its first Symantec antivirus for Macintosh (SAM).[36][37] SAM 2.0, released March 1990, incorporated technology allowing users to easily update SAM to intercept and eliminate new viruses, including many that didn't exist at the time of the program's release.[38]
In the end of the 1980s, in United Kingdom, Jan Hruska and Peter Lammer founded the security firm Sophos and began producing their first antivirus and encryption products. In the same period, in Hungary, also VirusBuster was founded (which has recently being incorporated by Sophos).
In 1990, in Spain, Mikel Urizarbarrena founded Panda Security (Panda Software at the time).[39] In Hungary, the security researcher Péter Szőr released the first version of Pasteur antivirus. In Italy, Gianfranco Tonello created the first version of VirIT eXplorer antivirus, then founded TG Soft one year later.[40]
In 2001, Tomasz Kojm released the first version of ClamAV, the first ever open source antivirus engine to be commercialised. In 2007, ClamAV was bought by Sourcefire,[53] which in turn was acquired by Cisco Systems in 2013.[54]
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