Computer Security

DoS and DDoS Attacks

A DoS attack stands for Denial of Service. A DoS is an attack on a network that is designed to interrupt or stop network traffic by flooding it with too many requests. A DDoS attack stands for Distributed Denial of Service. A DDoS attack launches a virus on a computer. Once the computers are infected they act as zombies and work together to send out legitimate messages creating huge volumes of network traffic resulting in a network crash.

Computer Virus

A computer virus is software that infects computers and is created using computer code. Computer viruses typically must be "run" to attack and do damage. Viruses can destroy programs or alter the operations of a computer or network.

Cookie

A cookie is a small text file of information created by websites you visit that your web browser stores on your hard disk. When you revisit a website that uses cookies your browser will send the cookie to the Web server which uses this information to customize and optimize your experience.

Cyberattack

A cyberattack is a deliberate misuse of computers and networks. Cyberattacks use malicious code to modify the normal operations of a computer or network, resulting in disruptions that can compromise data and lead to a variety cybercrimes.

Cyberterrorist

A cyberterrorist uses computers and the internet to launch attacks against computer systems for political or ideological reasons. Attacks include the disruption of ecommerce and government sites. The power grid and public utilities have also been targeted.

Worms

A destructive program that replicates itself throughout a single computer or across a network. Automatically reproduces itself. Designed to attack both wired and wireless networks. Replication exhausts network bandwidth or available storage.

Firewall

A firewall is hardware or software used to keep a computer secure from outside threats such as hackers and viruses. Firewalls allow or block Internet traffic in and out of a network or computer. An ideal firewall configuration consists of both hardware and software. Personal software firewalls are typically included with the operating system and can be configured based on user preference. Hardware based firewalls can be purchased as a stand-alone product but are often also included in broadband routers.

Script Kiddie

A hacker is a person who gains unauthorized access to networks in order to steal and corrupt information and data. Script kiddies try to illegally gain access to computer systems using programs (scripts) that others have written. Script kiddies do not have the skill or experience to write their own programs to gain illegal access to computer systems.

Hacker

A hacker is a person who gains unauthorized access to networks in order to steal and corrupt information and data. The term hacker and cracker are synonymous.

Keystroke logger

A keystroke logger is a form of spyware that records all actions typed on a keyboard. Can be hardware devices and software applications Software based keystroke loggers are often a Trojan that is installed without the user's knowledge. Keystroke loggers can record passwords and confidential information.

Macro Virus

A macro virus is a virus that is written in a macro language and placed within a document or spreadsheet. When the document or spreadsheet that has been infected by a virus is opened and the macro is executed, commands in the macro language set off the destructive events that the virus was designed for.

Trojan

A program that appears legitimate, but executes an unwanted activity when activated. Often used to find passwords, destroy data, or to bypass firewalls. Similar to viruses, but do not replicate themselves. Often found attached to free downloads and apps.

Rootkit

A rootkit is a type of malware that is triggered each time you boot your computer. Rootkits are software programs that hide in the operating system. A rootkit often allows for the installation of hidden files and for a remote user to use and take control of the computer.

Spam filter

A spam filter is computer software that is designed to prevent spam messages from entering a user's email inbox. Spam filters are also known as spam blockers or anti-spam utilities. Spam filters search for spam by watching for keywords and by monitoring suspicious word patterns and frequencies.

Email virus

A virus that is attached in a file and sent via e-mail. When the infected file is opened, the virus infects the computer. Phishing - tricks users into revealing usernames and passwords by appearing legitimate. Ransomware - when activated, encrypts files on user hard drive and then sells a decryption program. Keystroke logging Trojan - when activated, saves all keystrokes for subsequent transmission to virus creator.

Privacy risks with cookies

Cookies pose many potential privacy risks. Websites that use cookies can collect information about surfing habits and sell that information to a variety of third-parties. Websites can use cookies to track your surfing behavior and use this information to create specific user profiles. Corporate and government entities can use cookies to monitor your surfing behavior.

Cyberbullying

Cyberbullying is harming or harassing a person or group of people via information technology and networks in a repeated deliberate manner. Cyberbullies use Internet service and mobile technologies such as web pages and discussion groups as well as instant messaging and text messaging with the intention of harming another person. Cyberbullying is also known as cyberstalking.

Online nuisances

Online nuisances are annoying software programs that can slow down the operations of a computer, clog email inboxes, and lead to the theft of information and money. Online nuisances include: ---Spam ---Spyware ---Phishing and Pharming ---Trolling and Spoofing

Session Cookie

Session cookies are files that are stored in temporary memory. Session cookies are lost when the web browser is closed. Session cookies collect information about the start and end of a browsing session, analyze and measure web traffic on the web pages visited, and determine the web browser being used.

Diagnosing a hacked system

Signs your system might have been hacked include: Fake antivirus messages - If you notice these messages, power down your computer and reboot your computer in safe mode. In safe mode run your anti-virus program. Unwanted browser toolbars. Frequent random fake emails or social media messages from your account.

White Hat Hacker

White hat hackers are non-malicious computer security experts that test the security measures of an organization's information systems to ensure they are protected against malicious intrusions.

Adware

Adware is software that collects the user's web browsing history. This data is collected then used to create unsolicited targeted pop-up advertisements. Adware often accompanies downloaded programs.

Internet Filters

An Internet filter is firewall software used to block access to specific Internet content. Filters can be used by organizations, parents, and businesses to restrict access to file transfers, web sites, or Internet downloads. The software can reside in a router or user's computer, a stand-alone filter attached to a server or on a network. Internet/web filters are also called parental controls.

What if I get a phishing message?

Banks and credit card companies will never ask you to provide personal information via email messages, so do not give out any information. If you receive a suspicious message, contact the institution that the message was allegedly sent from. Report the incident to US-CERT.

Black Hat Hacker

Break into computer systems with the intent of causing damage or stealing data. Also known as hackers or crackers.

Password techniques

Change your passwords frequently. Use generic passwords. Keep your password private. Use a combination of letters, symbols, and numbers. Check your accounts.

Cybercrime

Cybercrime is criminal activity committed with a computer. Cybercrimes include cyberespionage, information theft, data manipulation, cyberbullying, and data corruption. The Office of Homeland Defense reported that cybercrime has increased by 400% in the last year. Cybercrime is a crime in which a computer is the object of the crime or is used to commit a crime or offense. There are two common types of cybercrimes, Single event and On-going series of events. Single event - Victims endure a single event cybercrime such as unknowingly downloading a Trojan horse virus, installing a keystroke logger, phishing, theft or manipulation of data via hacking or viruses, identity theft, or e-commerce fraud. On-going series of events - More serious than single event cybercrimes. On-going series of events include cyberstalking, child predation, extortion, blackmail, and terrorist activities.

Safe browsing tactics

Go Incognito - The four most popular web browsers have a private browsing option. Be cautious when using social media - Go to Facebook click on settings then download a copy of your Facebook data. Consider using a VPN - Virtual Private Networks (VPNs) are a very useful tool in protecting your online identity. HTTPS - Make sure the sites you are visiting have "https" at the beginning of the URL.

Hacktivist

Hacktivism is the act of hacking, or breaking into a computer system for a politically or socially motivated purpose. Individuals who take part in hacktivism are called hacktivists. Hacktivism uses the same techniques as a hacker, but does so in order to disrupt services and to bring attention to a political or social cause. Anonymous is one of the hacktivism groups that receives a lot of press.

Malware

Malware is short for malicious software. Malware is designed to steal information, destroy data, impact the operations of a computer or network, or frustrate the user. Malware includes a variety of programs including viruses, worms, and Trojan horses.

NAT

Network Address Translation (NAT) was developed by Cisco and is used by firewalls, routers, and computers that are part of a network and are connected to the Internet. NAT provides a type of firewall protection by hiding internal IP addresses. NAT can be used to prevent many types of network attacks, but in order to maximize security it must be used in conjunction with the firewall built into the router or the firewall provided by the OS.

How does antivirus software work?

One popular technique that antivirus software uses to detect viruses is to look for a virus signature, or virus definition. A virus signature is the software code of a particular computer virus. The antivirus program compares its database of known virus signatures with the files on a digital device and on removable media. Antivirus software companies are constantly searching for and updating their database of known signatures. It is important to make sure your antivirus program is on a regular update schedule. Once the virus is identified the antivirus software attempts to remove the virus. If the software cannot remove the virus it will send the file to an isolated area on the hard drive called a quarantine. Quarantined files will remain on your computer until you delete or restore them.

Persistent Cookie

Persistent cookies are stored on the hard drive and are not lost when the web browser is closed. Persistent cookies are only lost if they are designed with an expiration date. Persistent cookies collect information about user preferences, username and password information, IP address, and web surfing behavior.

Pharming

Pharming is a type of phishing that seeks to obtain personal information through malicious software that is deposited on a victim's computer. The malicious software redirects the user to a phony web page, even when the correct web address is used. When the user has reached the fake webpage they are prompted to enter their username, password, and other sensitive personal information.

Phishing

Phishing is the illegitimate use of an email message that appears to be from an established organization such as a bank, financial institution, or insurance company. In order to appear legitimate the message often contains the company's logo and identifying information. Phishing uses legitimate looking email messages to con a user into giving up private information such as account numbers, social security numbers and personal information. Phishing scams direct users to a fake website where they are asked to enter or update personal information.

Virus Symptoms

Some virus symptoms include: The operating system may not launch properly, and the computer user may need to reboot and restart the computer frequently to ensure all programs are starting and working fine. Critical files may get deleted automatically, and this can happen periodically or all at once. Error messages will become prevalent. It may become difficult to save documents, and the computer may be running slower than usual. If a system or network is infected severely, it may even black out or not even launch the startup process.

Avoiding Viruses

Some ways to help avoid viruses include downloading and installing the latest antivirus software and installing and running a firewall. Other ways to avoid viruses include only downloading software from trusted sites and only visiting trusted websites.

Spam

Spam is an unsolicited email message. Spam messages are sometimes called UBE, unsolicited bulk email, and are used for a variety of marketing purposes including selling products and services. Messages may contain a variety of malicious programs.

Packet Sniffer

Specialized hardware or software that capture packets transmitted over a network. Legitimate sniffers are used for routine examination and problem detection. Unauthorized sniffers are used to steal information. Packet sniffers can be very difficult to detect.

Spyware

Spyware is software that collects information about your Internet surfing habits and behaviors. Includes the collection of keystrokes, passwords, and confidential information. Often installed via free downloads or by visiting certain illegitimate websites

How a computer virus works

The virus arrives via email attachment, file download, or by "clicking" in an infected website. An action triggers the virus. The virus spreads to other computer/devices or networks. The activated virus starts its destructive actions.

How do firewalls work?

Typical firewall programs or hardware devices filter all information coming through the Internet to your network or computer system. There are a variety of techniques that are used to minimize the risk of harmful intrusions into a computer or network including packet filters and a proxy server. A packet filter inspects each packet leaving or entering a network and either accepts or rejects it based on a predetermined set of rules. Proxy Server - Intercept all messages between client and server and help avert a hacker or other intruder from attacking a network.

How does a virus infect a computer?

Viruses can affect a digital device in a number of ways including: ---Opening an infected Email attachment ---Downloading an infected file from the Internet ---Sharing infected files ---Visiting a contaminated Web site