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Showing posts with label Antivirous. Show all posts
Showing posts with label Antivirous. Show all posts

Saturday, June 25, 2016

Understanding Different Types of Viruses or Malware and What They Do

Whether you’ve had a computer for years or only a matter of days, it’s probably a good bet you have heard terms like malware, virus, trojan, keylogger, worm, rogueware, fake antivirus, rootkit, ransomware, adware, spyware or dialer. Most users will wonder what the differences between all these different words are as the word virus is often used as a generic term to cover all types of malicious activity on a computer.
Basically malware is short for Malicious Software and all of the terms above fall into this category because they are all malicious. The different terms being used instead of just plain virus are to categorize what the malicious software is capable of doing. For example, a keylogger is designed to record whatever keys you press on your keyboard and then send that information to a remote location. A trojan on the other hand, allows a hacker to steal information or gain full access to your computer.
Using the the word “virus” to include all types of malicious software is not very accurate, and “malware” is a more suitable term, a virus is after all just one type of malicious software. Thankfully most paid or free antivirus software looks for many different types of malware, not just viruses.Here’s a brief and easy to understand explanation for the majority of known forms of malware out there to help you differentiate between them.

Virus

The most known term, a virus is a piece of code that attaches to a program such as an executable file, then replicates itself and spreads to other files and onto other computers without your knowledge. When you run an infected file, the virus loads into memory and actively searches for other files to infect or infects files when they’re accessed by the system. The different effects caused by a virus range from annoying popups to corrupting and deleting files or even erasing the hard drive and are commonly transmitted through email attachments. An example of one of the most destructive virus was the CIH that is capable of corrupting the BIOS.

Rogueware / Scareware / Fake Software

There are a lot of names that fall into this category such as “fake antivirus”, “rogue antispyware” etc, but they all work toward the same goal. That is to scare or trick you into believing you have problems with your computer such as several viruses, the computer is being attacked by hackers, there are serious system stability issues or even that your hard drive is about to fail. The rogue software pretends to be legitimate software and will offer to repair the non existent problems if you buy their “software” which obviously is completely bogus.
example of rogueware
This type of malware is usually a form of worm or trojan often found in malicious emails and on adult, pirate video/music or hack/crack websites and requires the user to allow the program to run by tricking them into running a “scan” or downloading a “viewer” for a media file. They often disable running security software and also disable parts of the system such as task manager until removed. A few tools like Remove Fake Antivirus or RogueKiller can hep remove several types of this malicious software in addition to the excellent Malwarebytes Anti-Malware.

Trojan Horse

Unlike a virus, a Trojan horse doesn’t try to replicate itself but instead attempts to gain access to your PC and either looks to take control of it or steal information. A trojan usually achieves this by disguising itself as a legitimate program or a program you want to run such as a downloader, hack or crack etc, and the user executes the program to unwittingly activate the trojan. Below is a screenshot of DarkComet which is one of the popular and most used trojan.
trojan sample
They can often be used to also install other malicious programs such as key loggers or rogues onto your system. For more severe virus and trojan infections, you might need to download and boot with an antivirus boot CD.

Worm

Worms are similar in design to viruses in that they aim to replicate and infect as many systems as possible. The main difference being that Worms don’t need to attach themselves to other programs in order to spread to other computers and instead rely on networking (such as via emails) and other transfer mediums like USB flash drives to propagate. They can also cause network performance issues and slow down computers by consuming large amounts of memory.

Keylogger

keylogger sample
Keyloggers record all the keystrokes from a computer keyboard and that data is secretly logged. If a keylogger is being used maliciously, the logged data such as a typed document, online usernames and passwords, bank details etc, can be sent to a remote location or saved on the local computer without your knowledge. A keylogger can also be used for more legitimate purposes such as monitoring what your kids are typing in while using the internet etc. If you have had problems with keyloggers in the past or would like an extra layer of protection, you might like to try an anti-key logger software.

Dialer

With the modern internet connection usually being either DSL, cable or fiber, dialers are pretty much redundant because their main function is to dial an expensive premium rate telephone number instead of the number normally used to connect to your ISP. In the days of dialup and ISDN this was obviously a problem, but as modern broadband doesn’t dial phone numbers to connect, a dialer has no real effect.

Spyware

The simple definition of spyware is a piece of software that collects any information about you or your computer without your knowledge, and can send that information to a third party. In its lighter forms, spyware can simply track your browsing habits for serving ads or record your searches in toolbars etc. More serious forms of spyware can collect keystrokes, read cookies or files on the drive, spy on other programs and gather personal data. Spyware is often installed when other software is installed such as freeware or shareware applications which is why you should always take care when installing all forms of software.
Some of the most effective spyware removal tools such as Malwarebytes Anti-Malware, SUPERAntiSpyware and Spybot are also very good at removing adware, hijackers and rogueware.

Adware

adware sample
Advertising supported software (adware) is simply a piece of software that displays advertisements for other products to generate money for its developers which can be either inside the program itself or during the setup installation. This mostly occurs in free software and shareware programs by offering other products or toolbars etc, and really isn’t dangerous in itself, just mostly annoying, an irritant and difficult to uninstall. Some adware can serve its ads by tracking your browsing habits or activity, in which case it would be moved into the spyware category.

Browser Hijacker

Hijacking and changing your web browser start page and default search provider without consent can happen when installing certain toolbars or search helpers from software setup installers.
Browser hijack
It isn’t especially malicious, but can still be incredibly annoying, and quite often using the provided uninstaller doesn’t remove all traces and reset your settings completely.

Rootkit

Malicious rootkits often make their way onto a computer via software exploits or trojans and consist of a few parts. One part is to access the highest system privilege level (root) which can enable it to run high level actions, and the other (kit) is to deploy the malicious scripts, libraries or programs onto the system to perform the malicious tasks of stealing passwords, installing key loggers etc. Rootkits are stealthy and hard to detect because they start with your PC and activate very early in the boot process. Companies such as Sony and UbiSoft have been criticized in the past for using a form of rootkit in their DRM copy protections.

Ransomware

ransomware
Ransomware is like a more extreme version of rogueware and won’t just offer to repair non existing problems for a fee, it will actually demand a fee and can essentially lock you out of the computer, and in some cases also encrypt your files until you pay to remove it. A common ransomware recently is the Reveton worm which masquerades as a local police authority or other organization which accuses you of illegally downloading porn, warez or copyrighted material. You’re then told to pay a “fine” to unlock the computer. Ransomware often infiltrates a computer by downloading and running a malicious file in similar ways to rogueware or via email attachments. Windows Unlocker on the Kaspersky Rescue Disk is helpful in removing ransomware.
Note: Although there are several different categories of malware from looking at the list above, most of the malicious software today combines different kinds of malware to achieve a higher rate of infection and giving more control to the hacker. Most are invisible to the user and run silently without your knowledge to avoid detection and do as much damage as possible for as long as possible. Rogueware, ransomware and adware are designed to let you know they’re there. Just because it might not look like you have some form of malware on your computer, it doesn’t mean you don’t have anything malicious at all. Means to protect and scan your systems should always be to hand.
Read More:https://www.raymond.cc/blog/understanding-different-types-of-malware/

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List of 26 Bootable Antivirus Rescue CDs for Offline Scanning

A rescue CD is an additional tool provided by most antivirus companies to assist in removing difficult-to-remove malware without booting in to Windows. This is especially useful when the computer is so badly infected that Windows couldn’t be booted up, or is crawling really slowly and you can hardly run any diagnostic tools inside Windows to investigate and clean the virus.
A huge advantage in using a rescue CD compared to the antivirus installed on your computer is the chances of a successful removal is much higher because the malware is inactive since Windows is not even loaded in the first place. Unlike when a virus is active on the system, it can be very resilient and block any security tools from being run, making it really difficult even for experienced users to delete it from the system.
Rescue CD’s mostly come as an ISO image file that can be written to a compact disc (CD) or installed to USB flash drive which is then used to boot up the computer to run the live operating system in memory. Most of the rescue CD’s provided by the antivirus companies are free while there are a few that are exclusively available only to their paid customers. Here is an extensive list of 26 available rescue CD’s that can be downloaded and used for free.1. ArcaNix
ArcaNix
Price: Free
Operating System: Linux
File Size: 262MB
Format: ISO
Signature Update Method: Not Available
Default action(s) for detected items: Ask for action
Last Release: Updated daily
Additional Information: Has basic and advanced modes. The basic mode asks as few questions as possible while the advanced mode gives you complete control over the configuration. Testing shows that the scan is very slow and even missed a publicly released malware sample that we copied to the system.

2. AVG Rescue CD
AVG Rescue CD
Price: Free
Operating System: Linux
File Size: 85.9MB
Format: ISO and EXE (install to USB)
Signature Update Method: Online (Automatic), Offline and Download (Manual).
Default action(s) for detected items: Prompt for action (Heal, Rename, Delete, Report)
Last Release: 22 November 2012
Additional Information: Uses menu based selection and not graphical desktop environment. Comes with extra utilities such as Midnight Commander, TrueCrypt, Registry Editor, TestDisk, Smartctl, PhotoRec, Ping and Links. Allows you to install to a bootable USB flash drive from the main menu.

3. Avira AntiVir Rescue System
Avira AntiVir Rescue System
Price: Free
Operating System: Linux
File Size: 262MB
Format: ISO and EXE (burn to CD and save to ISO)
Signature Update Method: Online
Default action(s) for detected items: Repair, rename by adding .vir extension to the file if repair is not possible.
Last Release: Updated daily
Additional Information: Press Alt+F7 to return to graphical user interface if you accidentally end up in command line shell mode. You can launch Midnight Commander, a file manager to assist in backing up files by pressing Alt+F5 only from the shell.

4. Bitdefender Rescue CD
Bitdefender Rescue CD
Price: Free
Operating System: Linux
File Size: 379MB
Format: ISO
Signature Update Method: Auto online update on startup.
Default action(s) for detected items: Prompt for action (Disinfect, Rename, Delete)
Last Release: 06 July 2012
Additional Information: Can be installed to USB using UNetbootin . Comes with additional utilities such as GParted, TestDisk, Thunar File Manager, Firefox web browser and Foxit PDF reader.

5. Comodo Rescue Disk
Comodo Rescue Disk
Price: Free
Operating System: Linux
File Size: 50.5MB
Format: ISO
Signature Update Method: Online and Offline
Default action(s) for detected items: Prompt for action with clean (quarantine) option selected as default.
Last Release: 25 December 2012
Additional Information: Requires downloading more than 100MB of definition files before you can start scanning. Allows you to boot into graphic or text mode. Comes with PCMan File Manager, Midori web browser and screen capturing tool.

6. Dr.Web LiveCD
Dr.Web LiveCD
Price: Free
Operating System: Linux
File Size: 234MB
Format: ISO
Signature Update Method: Online
Default action(s) for detected items: Attempt to cure, and move to quarantine when failed to cure.
Last Release: 04 February 2013
Additional Information: You can create a LiveUSB by running the shortcut found on the desktop after booting with the LiveCD or download the independent LiveUSB installer . Comes with a mail client Sylpheed, Midnight Commander file manager, ePDFViewer, Firefox, and CureRegistry to fix the registry damages caused by a virus.

7. eScan Rescue Disk
eScan Rescue Disk
Price: Free
Operating System: Windows PE
File Size: 325MB
Format: ISO
Signature Update Method: Online
Default action(s) for detected items: Renames infected file by adding .mwt extension.
Last Release: 08 October 2012
Additional Information: Some scanning options such as startup folders, registry and spyware are disabled. Ability to launch a command prompt from the eScanAV AntiVirus Toolkit program.

8. ESET SysRescue
ESET SysRescue
Price: Available only to ESET users (paid and trial)
Operating System: Windows PE
File Size: 183MB (ISO)
Format: ISO, write to CD/DVD, install to USB
Signature Update Method: Online
Default action(s) for detected items: Automatically quarantine (delete) detected files.
Last Release: Not Applicable
Additional Information: ESET SysRescue can only be created from their security software Smart Security or NOD32. It requires Windows Automated Installation Kit (WAIK) which is 1.7GB in size installed on the computer to create the rescue disc.
9. F-Secure Rescue CD
F-Secure Rescue CD
Price: Free
Operating System: Linux
File Size: 140MB
Format: ISO
Signature Update Method: Automatic online update before scan and Offline method when definition file is stored in USB
Default action(s) for detected items: Auto disinfect and renamed if a file cannot be disinfected.
Last Release: 29 June 2012
Additional Information: Can be installed to USB using UNetbootin . The official user guide contains detailed step-by-step instructions on how to load the offline virus definition file from USB drive. It is also possible to automate the scanning process without user intervention by pre-loading the virus definition and creating a config file.

10. G Data Boot-CD 2013
G Data Boot-CD 2013
Price: Available only to G Data users (paid and trial)
Operating System: Linux
File Size: 264MB (ISO)
Format: write to CD/DVD, save as ISO
Signature Update Method: Online
Default action(s) for detected items: Instantly ask for action when virus is found.
Last Release: Not Applicable
Additional Information: G Data BootCD is a multi engine antivirus that uses avast! and Bitdefender. The BootCD can be created by clicking “More” at the top right of the program and select “Create boot CD”, or run the “Create G Data BootCD” shortcut from start menu.

11. Kaspersky Rescue Disk
Kaspersky Rescue Disk
Price: Free
Operating System: Linux
File Size: 282MB
Format: ISO
Signature Update Method: Online or Offline by adding a local source from the Settings area.
Default action(s) for detected items: Prompt for action when scan is completed.
Last Release: Updated daily
Additional Information: Allows you to boot in to graphic or text mode and view hardware information. Kaspersky Rescue Disk comes with Dolphin file manager, Kaspersky Registry Editor and Konqueror web browser. Can be installed to USB using their Kaspersky USB Rescue Disk Maker  tool (rescue2usb.exe). Sometimes the scan progress gets stuck at 99%. Take note that ZoneAlarm uses an older build of Kaspersky Rescue Disk.

12. Norton Bootable Recovery Tool
Norton Bootable Recovery Tool
Price: Requires Norton Product Key
Operating System: Windows PE
File Size: 628MB (ISO)
Format: A (.exe) downloader tool that can install to CD/DVD, USB and generate ISO.
Signature Update Method: Auto online update before scan is run.
Default action(s) for detected items: Prompt for action after finished scanning (Fix or Ignore). The fix action will remove the detected file from the original location, encrypt and store it in C:\NBRT\ folder for restoring the file.
Last Release: 22 August 2012
Additional Information: The installation wizard allows you to burn to CD/DVD, create ISO file, install on USB drive, update USB key definitions and add third party drivers. The installer will also automatically download any latest updates to be added to the bootable recovery tool. Do note that a valid Norton product key is required to be entered before you can scan. Upon further testing, we found that the Norton Bootable Recovery Tool even accepts expired and inactive product keys dating as far back as 2008.

13. Panda SafeCD
Panda SafeCD
Price: Free
Operating System: Linux
File Size: 245MB
Format: ISO
Signature Update Method: Online or Offline
Default action(s) for detected items: Automatically delete infected file.
Last Release: 03 April 2012
Additional Information: Old build but virus definition can still be updated.

14. PC Tools Alternate Operating System Scanner
PC Tools Alternate Operating System Scanner
Price: Free
Operating System: Linux
File Size: 234MB
Format: ISO
Signature Update Method: Not Available
Default action(s) for detected items: Confirm detected files to fix after scanning. The fixed files are renamed by adding .AOSS extension.
Last Release: Updated daily
Additional Information: Comes with additional utilities such as file recovery, file manager and disk detonator (wiping).

15. Quick Heal Emergency Disk
Quick Heal Emergency Disk
Price: Available only to Quick Heal users (paid and trial)
Operating System: Windows PE
File Size: 314MB for Quick Heal AntiVirus Pro 2013 + 124MB emgpkg32 zip archive
Format: write to CD/DVD, install to USB
Signature Update Method: Not Available
Default action(s) for detected items: Automatically delete detected items
Last Release: Not Applicable
Additional Information: You can create a free Quick Heal Emergency Disk from any of their desktop security products such as Quick Heal AntiVirus Pro 2013. After downloading, installing and activating the trial, go to Tools > and click on “Create Emergency Disk”. You are required to download the emergency disk package  according to your Windows system architecture, extract it and provide the extracted package folder path in Create Emergency Disk wizard.

16. Rising Antivirus Rescue CD
Rising Antivirus Rescue CD
Price: Free
Operating System: Linux
File Size: 86.9MB
Format: ISO
Signature Update Method: From USB created with “Backup VirusLib to U Disk” in Rising Antivirus. Refer to the official guide  for the step-by-step instructions.
Default action(s) for detected items: Ask for action at end of scan.
Last Release: 30 December 2010
Additional Information: Both the Rising Antivirus for Linux software and the definitions hard coded into the ISO rescue disc are very old. Updating the definitions is possible by loading them from USB which is quite troublesome to create.

17. Sophos Bootable Anti-Virus
Sophos Bootable Anti-Virus
Price: Free
Operating System: Linux
File Size: 136MB
Format: ISO
Signature Update Method: Not Available
Default action(s) for detected items: The “Recommended Scan” option prompts to confirm renaming the infected file upon detection.
Last Release: 26 October 2012
Additional Information: Requires several steps to create the ISO image file including usage of the command prompt. The detailed instructions can be found on this page .

18. Trend Micro Rescue Disk
Trend Micro Rescue Disk
Price: Free
Operating System: Linux
File Size: 55.6MB
Format: Installer can burn to disc or install to USB
Signature Update Method: Not Available
Default action(s) for detected items: Automatically move detected files to C:\TMRescueDisk\Session\ folder.
Last Release: 26 September 2012
Additional Information: Running the installer will first download the latest virus definition file around 13MB to embed into the rescue disk.
19. TrustPort System Rescue Disk
TrustPort System Rescue Disk
Price: Available only to TrustPort users (paid and trial)
Operating System: BartPE and Windows PE
File Size: 241MB (ISO Windows PE)
Format: BartPE plugin files and ISO for Windows PE
Signature Update Method: Online
Default action(s) for detected items: Automatically rename file extension by replacing the first character of the extension with the number 0. For example, .exe becomes .0xe
Last Release: Not Applicable
Additional Information: TrustPort is a multi-engine antivirus that uses a combination of the AVG and Bitdefender engines. Windows PE would be a better choice than BartPE because of the support for newer hardware and it is easier to create by just installing the Windows AIK. The only drawback is downloading the huge 1.7GB Windows AIK ISO file, extracting and installing it. After installing WAIK, click on the Antivirus drop down > More Functions > Prepare Windows PE CD.

20. VBA32 Rescue
vba32 rescue
Price: Free
Operating System: Linux
File Size: 130MB
Format: ISO
Signature Update Method: Online
Default action(s) for detected items: Attempt to cure and will delete if failed to cure.
Last Release: Updated daily
Additional Information: There are 2 ways to create a bootable USB for VBA32 Rescue. First method is to use their vba32rescue2usb  tool which will write the ISO to the USB and make it bootable and the second method is from the VBA32 Rescue environment by selecting the “Create bootable drive” option from menu.

21. VirusBuster Rescue CD
VirusBuster Rescue CD
Price: Free
Operating System: Linux
File Size: 143MB (ISO)
Format: ISO
Signature Update Method: Online
Default action(s) for detected items: Detected items moved to selected location and the file name will be be renamed to random characters without an extension.
Last Release: Updated daily
Additional Information: VirusBuster products has been withdrawn and Agnitum has acquired their antivirus technology. Oddly that their rescue CD is being recompiled daily to include the latest virus definitions. Other than scanning and cleaning virus, it comes with Midnight Commander file manager and the ability to restore Windows MBR.

22. Windows Defender Offline
Windows Defender Offline
Price: Free
Operating System: Windows PE
File Size: 282MB (ISO)
Format: A (.exe) downloader tool that can install to CD, DVD, USB and generate ISO.
Signature Update Method: Online
Default action(s) for detected items: Clicking the Clean PC button will delete the detected files.
Last Release: 13 September 2012
Additional Information: Using the downloader tool to create the CD, DVD, USB or ISO will automatically download and include the latest virus definitions. Windows Defender Offline is architecture dependent, meaning that if you’re trying to boot up a 32-bit Windows operating system, you will need a 32-bit version of the Windows Defender Offline instead of 64-bit.

23. Zillya! LiveCD
Zillya! LiveCD
Price: Free
Operating System: Linux
File Size: 538MB
Format: ISO
Signature Update Method: Not Available
Default action(s) for detected items: Prompt for action at the end of scan and only offer to delete.
Last Release: Updated weekly
Additional Information: Runs the Windows based Zillya! Scanner in Linux using Wine. Has a FAR file manager and MBR recovery tool to fix a corrupted master boot record.

24. Trinity Rescue Kit
Trinity Rescue Kit Virus Scanning
Price: Free
Operating System: Linux
File Size: 151MB
Format: ISO
Signature Update Method: Online
Last Release: 12 April 2011
Additional Information: Trinity Rescue Kit is a rescue disc that comes with a lot of useful utilities to help recover and rescue a Windows system. It contains 5 different antiviruses which is Clam AV, F-Prot, Bitdefender, Vexira(Not Working) and Avast. Clam AV is free to use while F-Prot and Bitdefender runs on trial license. As for Avast, it requires a license key to run. Do note that the computer must be connected to the Internet because each antivirus and latest definitions will only be downloaded upon selecting from the menu.

25. Anvi Rescue Disk
Anvi Rescue Disk
Price: Free
Operating System: Linux
File Size: 109MB
Format: ISO
Signature Update Method: Not Applicable
Last Release: 04 January 2013
Additional Information: Anvi Rescue Disk is not an antivirus but it aims to remove ransomware and boot sector viruses that are preventing you from booting into Windows. There are 3 scan modes and a registry fixer from the Repair tab that can be restored with a click. The ZIP archive also comes with a BootUsb.exe that allows you to install Anvi Rescue Disk to USB.

26. HitmanPro.Kickstart
HitmanPro.Kickstart
Price: Free to scan. Removal of detected items require software activation (paid or trial)
Operating System: Run on your Windows operating system
File Size: 131MB
Format: ISO
Signature Update Method: Not Applicable
Default action(s) for detected items: Quarantine (Delete)
Last Release: 19 December 2012
Additional Information: HitmanPro.Kickstart USB can be created from the HitmanPro program or simply download the provided ISO image file to burn to CD. It is designed to remove ransomware but can also remove any detected malware on your system by uploading suspicious files to their cloud servers to scan with 5 different antivirus engines (Bitdefender, Emsisoft, G Data, Dr.Web and Ikarus). HitmanPro.Kickstart is quite unique compared to the rest of the rescue disk because it runs on top of your Windows OS even if the malware is preventing you from accessing it.

Editor’s Noteavast! has a rescue disc  which is a shareware that cost $9.99 for the physical disc to be delivered via mail. Take note that it can take 10-15 days within EU and USA while other countries will take 15-25 days, making it an unsuitable rescue disc if you urgently need it. McAfee too has their own rescue disk called CleanBoot that runs on Windows PE. However it can only be downloaded with a proper grant number  provided by the McAfee Technical Support.
If you’re looking to combine multiple antivirus rescue discs and install a multi-boot USB flash drive,SARDU is a great tool to help you achieve that.
Read More:https://www.raymond.cc/blog/13-antivirus-rescue-cds-software-compared-in-search-for-the-best-rescue-disk/3/

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