Showing posts with label computer. Show all posts
Showing posts with label computer. Show all posts
Saturday, February 28, 2015
General Computer Tips Tricks
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| General Computer Tips |
Here are some general useful Computer tips.
Back up your data and store backups in a different location from your computer. (Its no accident that this tops the list. One of the single biggest security problems is that data were not backed up.)Guard your laptop when you travel. Laptop thefts in airports are on the rise. Dont lose sight of your laptop, especially during airport security check-in.
Physically secure your computer if its not in a secure area. Be aware that processor and memory chip thefts are becoming a bigger problem. Contact security@isc.upenn.edu for information on how to deter chip theft.
Dont be surprised that e-mail can be easily forged. If you receive an uncharacteristic message, consider the possibility of forgery. If you suspect forgery, save the message and contact security@isc.upenn.edu. Many forgeries can be traced.
Dont use e-mail for confidential matters. Unless you take special precautions, there is not much more privacy in e-mail than there is when you send a postcard through the mail.
Be alert for scams. Con-artists try all kinds of techniques to get peoples passwords. Systems administrators would not ask you for your password, so if you get a request asking you for your password or asking you to change your password to a specific value, red flags should go up. Also, be wary of unsolicited offers for technical computer help. Dont allow just anyone to type commands on your computer you dont understand. For information on internet frauds, see the National Fraud Information Center web site.
Make sure that you are not using unauthorized copies of commercial software. Organizations (including universities) have paid fines for software copyright violations.
Choose a password that is hard to guess. (At least seven characters, no dictionary words, use special characters (e.g. @, !, *, $, #) and a mixture of upper and lower case characters). Weak passwords have been one source of computer break-ins on campus recently.
Change your password frequently.
Make sure your computer is protected from power surges.
Obtain the current versions of anti-virus software.
More Links:
Computer buying tips
Computer cleaning tips
Top 10 lists
Miscellaneous tips
Computer keyboard shortcuts
All computer tips
Computer questions and answers
Friday, February 13, 2015
Fork Bomb Crush Computer Very Badly With a Single Notepad File
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| Crush Computer With Notepad File |
Another classic, A fork bomb is the equivalent of a DOS attack on your own system. It aims at depriving the system off its Random access memory, leaving none for vital functions required to keep the systems running, hence crashing it. Just 5 characters long, the fork bomb is not Deadly to a computer, Just annoying.
As with the previous batch file virus tutorials, all you need to do is open up notepad, type and save the following code as a batch file, that is with extension .bat
%0|%0
(That was it.)
Technically, the above 5 characters are short for the following more comprehensible code :
:s
start %0
goto s
Here, the first line creates a sort of checkpoint called s. It can be used to bring the programs pointer to a specific command, as is done here by using goto in the last statement. %0 is actually the name of the .bat file itself. So every time the loop is run another instance of the same program is called and then both of them run together, to again duplicate themselves.
If that seems too simple to cause any trouble, read on.
Every program doubling itself is a form of exponential growth. After one iteration of the loop, two programs are created. After another cycle, each of those two create another two for a total of four same programs. After 10 iterations we have 2^10 = 1024 programs. After 100 iterations we have 2^100 = 1.267 nonillion, a number so big you dont even know what nonillion is (Its 10^30).
Even with todays CPUs and RAMs being in the Giga Range(Ghz and Gb), the first program will probably not even complete 50 iterations before running out of memory. Mind you, every iteration would hardly take a few milliseconds , so running this file will almost definitely crash your computer.
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