INTERNET SECURITY, VIRUS & ANTIVIRUS
Trojan horses disguise themselves as valuable and useful software available for download on the Internet. They are programs that open a backdoor so the hacker can enter the client’s network at will.
Remote Access Trojans are the most frequently available ones. These give an attacker absolute control over the victim’s computers. The attacker can go through the files and access any personal information about the user that may be stored in the files, such as credit card numbers, passwords, and vital financial documents. A trojan horse is typically separated into two parts – a server and client. It is the client that is cleverly disguised as significant software and positioned in peer-to-peer file sharing networks or unauthorized download websites. Once the client Trojan executes on a computer, the attacker (i.e. the person running the server), has a high level of control over that computer, which can lead to destructive effects depending on the attacker’s purpose.
Password Sending Trojans
A Password Sending Trojan’s intention is to copy all the cached passwords, look for other passwords as they are keyed into a computer, and send them to particular email addresses. These actions are performed without the users’ awareness. Passwords for restricted websites, messaging services, FTP services, and email services come under direct threat with this kind of trojan.
Key Loggers
Key Loggers is a type of Trojan that logs victims’ keystrokes and sends the log files to the attacker. It then searches for passwords or other sensitive data in the log files. Most Key Loggers come with two functions, online and offline recording. Of course, they can be configured to send the log file to a specific email address on a daily basis.
Spyware is a program on the hard dirve that sends information about how you use a PC to marketers and advertisers. Antivirus software and firewalls do nothing to block spyware installed with a download that the user asks for. Spyware can be hidden under the Window’s Registry, where is harder to find.
Firewall manager software set up rules to filter out unwanted intrusions from internet. The firewall examines each packet, and if the outbound address of the data is on a list of banned internet locations it will block it. Another way to keep hacker out is all traffic thru a proxy file server, which examines all data based on the filtering rules and only forward packet obey the rules. Firewall manager also add the intrusions to a security log and reports to internet service provider or to helpdesk/IT staffs.
How Viruses Invade
Virus is created when a programmer intentionally infects a program or disk with computer code that has the capability to replicate itself, hide, watch for specific event to occur.
Boot record viruses target the master boot record. Program viruses look for executable .com and .exe program files and inserts its copy behind program header.
Memory resident virus can watch for attempts by antivirus software to find infected files and return phony information to hide from detection.
Viruses can traveler thru internet by email attachment or HTML hyperlink.
How Anti-virus Software Works
Anti-virus software inspects the master boot record, program files, and marco code for the present viruses. Signature scanners look at the contents of the boot record. Because stealth virus evades detection by signature scanners, heuristic detectors look for section of code triggered by time, routines to search for .COM and .EXE files, and disk writes that bypass the operation systems. To remove viruese in the memory, the software monitor all the modified program code, or programs that try to remain in memory after they are executed.
