Showing posts with label viruses. Show all posts
Showing posts with label viruses. Show all posts

Tuesday, September 10, 2013

What is Malware?

Protecting your computer from malicious software is perhaps the most important aspect of computer ownership.
A wide range of products are available that offer computer security. However, did you know that certain products only offer protection against a few malicious attacks? Are you concerned that your computer may not be fully secured? Before you take the necessary measures of securing your computer, you should understand the different types of attacks that could harm your machine.
What is Malware?
Malicious software (malware) is the wide range of software applications developed with a malicious intent. The methods used for malware installation is unlike any other software installation you are accustomed to because malware is installed through devious means. People often use the terms virus and malware interchangeably. However, a virus is a type of malware. Other major malware types include:
Virus

A virus contains malicious code that attaches itself to an application. When the infected application is executed, the virus is launched and will attempt to spread to other computers. A virus typically will not cause immediate damage as it needs time to replicate in order to infect other computers. Eventually, the virus will deliver its payload. The payload can cause significant damage such as deletion of critical system files, random reboots of your computer, and can corrupt hard drives and make them unbootable. Viruses are delivered to systems in a variety of ways. Email is the most common method for spreading viruses. For example, spammers will email viruses as attachments and will entice users to download and open the attachment, which in turn will execute the virus. Users can also transmit viruses by using infected USB flash drives. Most operating systems have Autorun enabled, which enable infected USB flash drives to execute the virus as soon as the device is plugged into the machine.


Trojan Horse

Trojan horses trick users by posing as legitimate applications. For example, a Trojan horse may appear to be a game or a screensaver. A deceived user will download the application and the Trojan horse is released once the user executes the program.
Worms

Unlike viruses and Trojan horses, worms do not need to be executed. Worms reside within memory and can travel throughout a network without depending on an infected computer application or interaction. Worms replicate themselves exponentially and can literally crash networks by consuming its bandwidth.

Spyware

Spyware is installed on a machine without the user’s awareness or consent. Spyware attempts to gather specific user information and send it to a third party. You can determine if your computer is infected with spyware if your Internet home page has suddenly changed, if your web browser redirects web searches, or if additional software has been installed on your machine. Another form of spyware is adware. Adware launches pop-up windows to display unwanted advertisements.

Logic Bombs

A logic bomb is malicious code embedded within an application that executes based on certain events. The logic bomb lies dormant until that event occurs. The event may be when a specific date is reached or if an employee’s record is removed from an organization’s payroll information system.
Rootkits

A rootkit is the combination of programs designed to infect your computer without being detected. Your antivirus application communicates with your operating system to identify threats. However, rootkits breaks down this communication process. Consequently, your antivirus software will think that everything is fine and will not report that your computer is infected.

You can find security tools that will protect your computer from the above threats. In most cases, one tool is not enough. You may need to use a combination of utilities to fully project your system. Understanding the major types of malware can help you make informed decisions about acquiring tools to project your computer.

Tuesday, September 3, 2013

How to remove Virus from USB Drives ?

One of the ways by which a virus can infect your PC is through USB/Pen drives. Common viruses
such as ’Ravmon’ , ‘New Folder.exe’, ‘Orkut is banned’ etc are spreading through USB drives. Most
anti virus programs are unable to detect them and even if they do, in most cases they are unable to
delete the file, only quarantine it. Here are the things which you can do if you want to remove such
viruses from your USB drives.
1. Whenever you plug a USB drive in your system, a window will appear similar to the one
shown below
2. Don’t click on Ok , just choose ‘Cancel’.
3. Open the Command Prompt by typing ‘cmd‘ in the run box.
4. In the command prompt type the drive letter: and press enter.
5. Now type dir /w/a and press enter.
6. This will display a list of the files in the pen drive. Check whether the following files are there
or not:
Autorun.inf
• Ravmon.exe
• New Folder.exe
• svchost.exe
• Heap41a
• or any other exe file which may be suspicious.
7. If any of the above files are there, then probably the USB drive is infected.
8. In command prompt type attrib -r -a -s -h *.* and press enter.
9. This will remove the Read Only, Archive, System and hidden file attribute from all the files.
10. Now just delete the files using the command del filename. --
Example del Ravmon.exe. -
Delete all the files that are suspicious.
Example:
• Microsoft Windows XP [Version 5.1.2600]
• (C) Copyright 1985-2001 Microsoft Corp.

• L:\Documents and Settings\kayzg>o:
• O:\>

• O:\>dir /w/ac
• Volume in drive O is KAYZGPEKEE2
• Volume Serial Number is D834-F037
• Directory of O:\
• [untitled folder] [System]
• [Documents] winzip90.exe
• sdat5277.exe LaunchU3.exe
• ethereal-setup-0.99.0.exe ethereal 1.doc
• PROJECT NETWORK MANAGEMENT.doc About the Raila Virus 1.doc
• About the Raila Virus.doc KAYUMBO G.doc
• 9 File(s) 63,575,709 bytes
• 3 Dir(s) 547,983,360 bytes free
• O:\>
• O:\>del Autorun.inf
• Could Not Find O:\Autorun.inf
• O:\>
11. To be on a safer side, just scan the USB drive with an anti virus program to check whether it is
free of virus or not.
12. Now remove the drive and plug it again. In most of the cases, the real culprit turns out to be the
“Autorun.inf” file which mostly gets executed when someone clicks Ok in the dialog window
which appears above. Thus the infections can spread
Security Tips
1. Disable the Autoplay feature of USB drives. If you disable the Autoplay feature of USB drives,
then there are lesser chances of the virus spreading.
2. A tool which can perform such a function is Tweak UI. Download it from here and install it.
3. Now you can disable the Autoplay feature of the removable drives as shown above.
4. Run the program, expand My Computer, AutoPlay, and then click Types. On the right panel under
AutoDrives Types un-tick Enable Autoplay for removable drives.
5. By following the above steps, you can keep your USB drives clean.
Other simple ways
1. Don’t loan your flash drive to anyone. If you do you're taking a risk there. Lending your flash
card is not a good idea. You don't know what’s on your friend’s computer or what worm will
work its way to your flash drive then to your computer.
2. When you insert it to your USB port run your anti virus scanner on it first. BEFORE YOU
OPEN THE DRIVE!!!! If it is infected it will tell you.
3. Make sure you update your anti virus program first. Anytime you hook anything to your
computer scan for virus before you open it.
How to quickly scan your flash drive
1. When you connect the flash drive, before open your flash drive:
• Right click [on removable disk, ]
scan with antivirus then you can use,
• If you are going to copy any file from your pc, first scan the particular then only copy to your
flash drive.