The Decalogue to defend against infections
Prevent infections, it has become an absolute necessity: for this reason there are special software, called viruses. But sometimes, these are not sufficient, and be put in place prevention systems that require a daily commitment, and above all, adhere to rules of conduct quite simple. Here are ten tips to avoid contracting computer virus. These are some of the most important, not all. Make good use.
Prevention is nothing without control
Assuming that your system is a good antivirus installed, run a regular scan of the system. Some viruses may hide in system folders, or even in the temporary folder of your browser. To launch AVG scan, click on the button “Run full test.” Once you have identified a virus, the virus usually clears, clearing the infected file. If this is not possible, the file is quarantined. At this point it is necessary to determine whether the file is needed (eg a file system) or not. In the second case, the document can be eliminated by solving the root problem. If the file is indispensable, however, the only alternative is to wait for an update of the antivirus that can eradicate the infection. The quarantined files, meanwhile, can not be used. Computer Virus
To make sure that antivirus software is reliable, it must be constantly updated, which receives regularly (daily or even several times a day) the new definitions of latest viruses, the new list of virus signatures. Some laboratories employ a few hours, or even less, to develop a “cure” for new viruses detected.
Connect to the Internet and then you match the update of your antivirus software: AVG just press the button “Virus Database“. If you want to receive regular updates and automatic, you simply go to the menu Service / Schedule and Update (or press the key combination Ctrl + F9) in the window that appears, custom data parameters (if necessary, even in the advanced settings).
Java does not profit you!
Be careful while browsing, to ActiveX and Java applets. These functions allow the automatic execution of programs that could be harmful. A concrete example of this type of virus was “Java.BeanHive,” a small virus consists of 40 lines of code that, after infecting a macro (via the Java Machine), was connected to a Web server, initiated the bulk of the virus, infecting all Java programs. In practice: the files were infected with a small portion of the virus, whose main part remained online. A really sneaky, and very effective
You can completely disable the display of the Java applet in order to avoid problems of this kind finally: If you use Internet Explorer, go to Tools / Options and remove the check mark next to “Java JIT compiler enabled”.
Do not open that attachment!
Never open an attachment received in e-mail before passing it through a sieve with the virus, even if it comes from someone you know. The following are the most common extensions of viruses that spread through e-mail
The trick of double extensions
Pay close attention to the trick of double extensions (for example used by the virus “Anna Kournikova” and BugBear). A file attachment with the seemingly innocuous, may hide another (for example “. TXT.VBS”). In some cases, this trick can take in chestnut antivirus software. Recently, this system has been used by sneaky Netsky worm.
In addition to the duty to advise you not to open suspicious files, another way to prevent infection is to force Windows to show all file extensions, even those associated with the most common applications (which usually hides). Open Windows Explorer and go to Tools / Folder Options and remove the check mark from the phrase “Hide extensions for known file types.”
In any case, the antivirus AVG is able to recognize the double extensions.
The infection in preview …
Sometimes it is not enough to focus on attachments: some viruses, particularly devious, using a refined technique, inserting the text of the e-mail a reference to an Internet site that starts in automatic virus. Thus, even viewing the message content, you may be infected. This system is called “Popup Object Exploit”, and takes advantage of security flaws in some e-mail programs such as Outlook Express. If you use this e-mail program, it is necessary to inhibit the preview (previewing) of the message. Go to View / Layout and remove the checkmark next to “Show preview pane”.
- Microsoft plugged the holes!
Viruses often seek to exploit security flaws in the programs (operating systems, or other applications) installed on your computer. The software manufacturers are conscious and try to run for cover, once found a “bug” in the shortest possible time. Microsoft, for example, provides constant updates for their products. To download simply go to Start / All Programs / Windows update. Or you can connect directly to the Microsoft website, at windowsupdate.com .
- Check your mail without download
If, despite previous advice, do you think that downloading mail on your computer is not secure, there is a method to test for any infection. Check e-mail without download, directly on the server or through a Web-based email. In the first case, it is necessary to adopt special programs that allow you to view your e-mails without downloading them on your PC. One of these is, for example, MailWasher: you can download it for free at the Internet www.mailwasher.net . The Step by Step on its operation has been published in issue 101.
- The macro viruses
Often viruses are hidden in files that, apparently, should be safe. For example, Word files and Excel. In some cases, these documents do not contain only ASCII characters (text or numbers or other typographical signs) but also of macro, ie automated procedures that allow you to save a series of operations, then called up with a simple command (or a key). The viruses that lurk there also are written with the macro programming language (typically, the Visual Basic), it auto start when the document remain resident in memory (and are saved in the file “Normal.dot “) and infect all files of the same type.
How did you realize you have contracted a macro virus? In general, it is unable to convert the infected document to other formats and you can not even use the “Save As”.
To increase control over macro, open the Microsoft program (eg Word, but the commands are common to all the other applications of the Office package) and go to Tools / Macro / Security and put a check mark next to the first option: ” Very high. ” In any case, the anti-virus AVG checks all macros of Office documents, automatically.
- The streets of the virus are endless
When the network still had not reached the current Internet diffusion, the best way to peck a virus was to spread an infected floppy disk. Now things have changed radically. The danger can lurk anywhere, on-line, and you should always be careful where you surf, and most importantly, what you download.
When you visit unsafe sites, do not download the file. Yet viruses that are transmitted via the Internet can also find a special channel in connections via instant messenger like ICQ, mIRC, or the like. Do not consent to receive suspicious files, not just executables; even compressed archives with extension ZIP and RAR can hide unpleasant surprises. Recently, Kaspersky Labs have issued a statement in which they warn about the danger of Bizex, a worm that spreads through ICQ.
Even the peer to peer network is not immune from the contagion is the case, for example, the worm Benjamin, who in 2002 struck the users of the Kazaa software.