Virus and its types 2
- 2. What is virus What is a computer virus? • A computer virus is a type of malware that, when executed, replicates by inserting copies of itself (possibly modified) into other computer programs, data files , or the boot sector of the hard drive; when this replication succeeds, the affected areas are then said to be "infected". Viruses often perform some type of harmful activity on infected hosts, such as stealing hard disk space or CPU time, accessing private information, corrupting data. However, not all viruses carry a destructive payload or attempt to hide themselves. • The vast majority of viruses (over 99%) target systems running Microsoft Windows, employing a variety of mechanisms to infect new hosts, and often using complex anti-detection/stealth strategies to evade antivirus software.
- 3. How a computer virus spreads? For a computer virus to spread through a computer system, or network, it must be activated. This means that the file that contains the virus must be opened, or executed in order for the virus to come to life. After it gets activated, these viruses look for certain programs to infect. The main and the important that you must note is that, all viruses seem to do well is duplicate themselves within the programs they find, and this is the main reason as to how they spread well. 1. Email attachments. 2. Rogue Websites. 3. Hackers/fake Anti Virus Software
- 4. TYPES OF VIRUS Types of computer viruses • Trojan Horse A program written to deliver a malicious program that may then cause destruction to your computer. A Trojan horse is delivered by someone or hidden within another program that may seem harmless. • Spyware A program written to monitor your actions on a computer. A common type of spyware is a key-logger program. This program can record every key stroke and mouse click you make. Spyware can be delivered via a Trojan horse program.
- 5. • Boot Sector Virus Not so common anymore, but they were nasty little programs that got loaded into your master boot record. Most commonly spread by floppy disks. These viruses could then launch themselves before your operating system even loaded. • Time Bomb A virus written to execute at a later date or upon an action performed. These programs lay dormant until an event occurs. • Browser Hijacker A virus that will over take your web browser and automatically redirect you to another website. • File Infector Virus A virus that lives within a file, typically a .exe file. When the file is executed, it will then run its nasty code.
- 6. • Adware Adware is a form of malware. One word - pop-ups. Adware is designed to pop up advertisements. Adware can be very annoying. • Worms Just a nasty little program to cause slowness in a network. A worm will replicate itself and spread from computer to computer. Worms are commonly spread through email attachments. • Polymorphic Virus A virus written to change itself in order to evade virus detection.
- 7. Ransomware • Ransomware is a type of malicious software from cryptovirology that threatens to publish the victim's data or perpetually block access to it unless a ransom is paid. While some simple ransomware may lock the system in a way which is not difficult for a knowledgeable person to reverse, more advanced malware uses a technique called cryptoviral extortion, in which it encrypts the victim's files, making them inaccessible, and demands a ransom payment to decrypt them.In a properly implemented cryptoviral extortion attack, recovering the files without the decryption key is an intractable problem – and difficult to trace digital currencies such as Ukash and Bitcoin are used for the ransoms, making tracing and prosecuting the perpetrators difficult.
- 8. Ransomware attacks are typically carried out using a Trojan that is disguised as a legitimate file that the user is tricked into downloading or opening when it arrives as an email attachment. However, one high- profile example, the "WannaCry worm", traveled automatically between computers without user interaction.
- 9. THANK YOU
Editor's Notes
- #8: Mostly this virus is sent through email and it has extension of .exe or bat file