What is a Zero-Day Vulnerability?

A zero day vulnerability refers to a hole in software that is unknown to the vendor. This security hole is then exploited by hackers before the vendor becomes aware and hurries to fix it—this exploit is called a zero day attack. Uses of zero day attacks can include infiltrating malware, spyware or allowing unwanted access to user information. The term “zero day” refers to the unknown nature of the hole to those outside of the hackers, specifically, the developers. Once the vulnerability becomes known, a race begins for the developer, who must protect users.
In order for the vendor to rectify the vulnerability, the software company must release a patch. Often patches are released on a regular basis, one example being Microsoft’s Patch Tuesday. On the second Tuesday of each month, Microsoft releases security fixes that resolve identified holes. If, however, a critical vulnerability is discovered, a patch may be released outside of schedule.
Browsers are similarly vulnerable; it’s a good idea to update your browser often, for updated security as well as features. To check if any updates are available for your browser of choice, open the browser and click either “Help” or the browser name, depending on which browser you’re using. A quick online search will provide step-by-step instructions. Alternately, you could set up automatic updates, again, depending on browser.
zero-day-updates
Zero day vulnerabilities can be serious security risks. When searching for an appropriate antivirus solution, look for security software that protects against both known and unknown threats.

http://www.pctools.com/security-news/zero-day-vulnerability/

What is the difference between shutdown and restart?

Question : What is the difference between shutdown and restart? I am under the impression that shutdown closes ALL processes, completely clears the RAM, and clears the processor cache. I need to know if 1) this is a correct assumption, and 2) which is better for daily system maintenance. Thank you in advance.

Answer : Your assumption on shutdown is correct. Basically it shuts down all processes and turns your computer off completely. Restart, on the other hand, temporarily shuts down your PC then fires it up again. This usually happens when Windows Updates are installed. After the install the system is restarted (re-booted) to ensure that any update has been installed correctly and is working as it should. You may be slightly mixed up with restarting and hibernation.

Restarting is, as I have stated above, basically a reboot of your machine. In the end your PC is On again after a restart. Hibernation, on the other hand saves all data currently in memory to a special file then turns the PC off. When you next switch your PC on, i.e., coming out of hibernation, the hibernation files is used to restore you PC's condition to that of when you initially hibernated. In other word any programs you had open previously to hibernating will again automatically open and be ready for you to use.

 Hibernation or sleep for that matter is for short term use. It is okay to hibernate or sleep if you are going to be away from your PC for half an hour or so. If you will be away longer than that I suggest you shutdown completely. A point to remember regarding hibernation is that, if you use hibernate, you cannot, once you subsequently come out of hibernation, install any programs or updates. You have to shutdown and reboot normally to do this.

This forum post is my own opinion and does not necessarily reflect the opinion or view of Microsoft, its employees, or other MVPs.

http://answers.microsoft.com/en-us/windows/forum/windows_7-desktop/what-is-the-difference-between-shutdown-and/dce1deb2-f866-47d0-b364-3980f24fe34c

Şifreniz Uzun Olsun

Araştırmalara göre karışık, karma ve kısa şifrelerden ziyade, uzun rastgele seçilen kelimler şifre güvenliği için daha etkilidir.



Kaynak: http://arstechnica.com/business/2012/03/passphrases-only-marginally-more-secure-than-passwords-because-of-poor-choices/