• The computer screen blinks, flips
  upside-down, or is inverted so that
  everything is displayed backward
• The default background or wal lpaper settings change automatically
• Web pages suddenly open without input from the user
• The color settings of the operating system (OS) change automatically
• Antivirus programs are automatically disabled
• Pop-ups with bizarre messages suddenly appear

• Inflict damage on competitors
• Realize financial benefits
• Vandalize intellectual property
• Play pranks
• Conduct research
• Engage in cyber-terrorism
• Distribute polit ical messages
• Damage network s or computers
• Gain remote access to a victim's computer

• A type of malware that restricts access to the computer system's files and folders
• Demands an on line ransom payment to the malware creator(s) to remove the restrictions
• Example : Dharma
  

• Malicious programs that independently replicate, execute, and spread across the network connections
• Consume avai lable computing resources without human interaction
• Attackers use worm payloads to install backdoors in infected computers
• work အလုပ်လုပ်ပုံ
  

• Attackers use worm payloads to install backdoors on infected computers, which turns them into zombies and creates a botnet. Attackers use these botnets to initiate cyber-attacks. Some of the latest computer worms are as follows
  🐛 Manero
  🐛 Bondat
  🐛 Beapy

• A virus infects a system by inserting it self into a file or executable program
• It might de l ete or alter the content of files or change the location of files in the system
• It alters the way a computer system operates without the knowledge or consent of a user
• A virus cannot spread to other computers unless an infected fi le is repl icated and sent to the other computers
• A virus spreads at a uniform rate, as programmed
• Viruses are difficult to remove from infected machines

• A worm infects a system by exploiting a vulnerability in an OS or application by replicating itself
• Typically, a worm does not modify any stored programs; it only exploits t he CPU and memory
• It consumes network bandwidth, system memory, etc., excessively over loading servers and computer of a user systems
• A worm can replicate itself and spread using IRC, Outlook, or other applicable mailing programs after installation in a system
• A worm spreads more rapid ly than a virus
• Compared with a virus, a worm can be removed machines easily from a system

Attackers use worm pa yloads to install backdoors on infected computers, which turns them into zombies and creates a botnet. Attacker s use these botnets to initiate cyber-attacks. Some of the latest computer worms are as follows:

• Manero
• Bondat
• Beapy

• Internet Worm Maker Thing
• Batch Worm Generator
• C++ Worm Generator

• Rootkits are programs that hide their presence as well as attacker's malicious activities, granting them full access to the server or host at that time, and in the future
• Rootkits replace certain operating system calls and utilities with their ow n modified versions of those routines that, in turn, undermine the security of the target system causing malicious functions to be executed
• A typical rootkit comprises of backdoor programs, DDoS programs, packet sniffers, log-wiping utilities, I RC bots, etc.

Scanning for vulnerable computers and servers on the web
Wrapping it in a special package like a game
Installing it on public computers or corporate computers through social engineering
Launching a zero-day attack (privilege escalation, buffer overflow, Windows kernel exploitation, etc.)

To root the host system and gain remote backdoor access
To mask attacker tracks and presence of malicious applications or processes
To gather sensitive data, network traffic, etc. from the system to which attackers might be restricted or possess no access
To store other malicious programs on the system and act as a server resource for bot updates

• Also known as grayware or junkware, are potentially harmful applications that may pose severe risks to the security and privacy of data stored in the system where they are installed
• Installed when downloading and installing freeware using a third-party installer or when accepting a misleading license agreement
• Covertly monitor and alter the data or settings in the system, similarly to other malware
• TypesofPUAs
• Adware
• Torrent
• Marketing
• Cryptomining
• Dialers

Types of PUAs
■ Adware: These PUAs display unsolicited advertisements offering free sales and pop-ups of online services when browsing websites. They may disturb normal activities and lure victims into clicking on malicious U Rls. They may also issue bogus reminders regarding outdated software or OS.
■ Torrent: When using torrent applications for downloading large files, the user may be compelled to download unwanted programs that have features of peer-to-peer file sharing.
■ Marketing: Marketing PUAs monitor the online activities performed by users and send browser details and information regarding personal interests to third-party app owners. These applications then market products and resources based on users' personal interests.
■ Cryptomining: Cryptomining PUAs make use of the victims' personal assets and financial data on the system and perform the digital mining of cryptocurrencies such as bitcoins
■ Dialers: Dialers or spyware dialers are programs that get installed and configured in a system automatically to call a set of contacts at several locations without the user's consent. Dialers cause massive telephone bills and are sometimes very difficult to locate and delete.

• Fileless malware, also known as non-malware, infects legitimate software, applications, and other protocols existing in the system to perform various malicious activities
• Leverages any existing vulnerabilities to infect the system
• Resides in the system's RAM
• Injects malicious code into the running processes such as Microsoft Word, Flash, Adobe PDF Reader, Javascript, and PowerShell

• Stealth: Fileless malware exploits legitimate system tools; hence, it is extremely difficult to detect, block, or prevent fileless attacks
• LOL "Living-off-the-land": System tools exploited by fileless malware are already installed in the system by default. An attacker does not need to create and install custom tools on the target system
• Trustworthy: The system tools used by fileless malware are the most frequently used and trusted tools; hence, security tools incorrectly assume that such tools are running for a legitimate purpose>

• Phishing emails
• Legitimate applications
• Native applications
• Infection through lateral movement
• Malicious websites
• Registry manipulation:
• Memory code injection
• Script-based injection