Good morning people. How are you people? Here's some information about Proxy Server.

A proxy server is a computer that offers a computer network service to allow clients to make indirect network connections to other network connections. A client connects to the proxy server, then requests a connection, file or other resources available on a different server. The proxy provides the resource either by connecting to the specified server or by serving it from a cache. In some cases, the proxy may alter the client's request or the server's response for various purposes.

Types:

1. Web

2. SSL

3. Intercepting

4. Open

5. Reverse

6. Split

7. Circumventor

8. Anonymous

Thats all for today. Have a nice day. 

Good evening people. How are you all today? I would like to share information about Malicious Software: Viruses, Worms, Trojan Horses and Spyware.

Malicious software programs refered to as malware include a variety of threats such as computer viruses, worms and trojan horses. A computer virus is a rogue software program that attaches itself to other software programs or data files in order to be executed, usually without the user knowledge or permission. Most computer viruses deliver a "payload". The payload may be relatively benign, such as the instructions to display a message or image, it may be highly destructive - destroying programs or data, clogging computer memory, reformatting a computer's hard drive or causing programs to run improperly. Viruses typically spread from computer to computer when humans take an action as sending e-mail attachments or coping an infected file.

Many recent attacks have come from worms, which are independent computer-programs to copy themselves from one computer to others over a network. Unlike viruses, they can operate on their own without attaching to other computer program files and rely less on human behaviour in order to spread from computer to computer. Worms can destroy data and programs well as disrupt or even halt the operation of computer networks.

Worms and viruses are often spread over the Internet from files or downloaded software, from files attached to e-mail transmissions, or from compromised e-mail messages. Viruses have also invaded computerized information systems from "infected" disks or infected machines. Today e-mail attachments are the most frequent source of infection, followed by Internet downloads and Web browsing.

A Trojan horse is a software program that appears to be benign, but then does something other than expected. The Trojan horse is not itself a virus because it does not replicate, but is often a way for viruses or other malicious code to be introduced into a computer system. An example of a modern-day Trojan horse is Trojan.Xombe, which was detected on the Internet in early 2004. It masqueraded as an e-mail message from Microsoft, directing recipients to open an attached file that purportedly carried an update to the Windows XP operating system. When the attached files opened, it downloaded and installed malicious code on the compromised computer. Once this Trojan horse was installed, hackers could access the computer undetected, steal passwords and take over the machine to launch denial of service attacks on other computers.

Some types of spyware can also act as malicious software. These small programs install themselves on computers to monitor user Web surfing activity and serve up advertising. Some Web advitisers use spyware to obtain information about users' buying habits and to serve tailored advertisments. Many users find such spyware annoying and some critics worry about its infrigement on computer users' privacy.

Thats all for today. Have a nice day. 

The types of resources targeted in denial-of-service attacks include the following:
• CPU utilization
• Disk space and I/O
• Memory utilization
• Network bandwidth

Techniques for denial-of-service are harder to identify than for system/ network penetration because they tend to be application or environment specific. Some common techniques for denial-of-service include the following:

Application or protocol exploits. These may appropriate specific application or protocol features to effect a denial-of-service; an example might be the appropriation of a protocol authentication or cache mechanism to effect denial-of-service.

Buffer overflows. Denial-of-service buffer overflows generally attempt to exhaust system resources or exploit an application vulnerability in executing code to crash an operating system or application component.

Malformed packet data. Malformed packet data may be forwarded to a target system with a vulnerable TCP/IP stack implementation or application service as a means of crashing a system or system/network  resource.

Packet flooding. Packet flooding attempts to exhaust network bandwidth or system bandwidth as a means of denying access to targeted resources.

The objective of most denial-of-service attacks is to effect excessive resource consumption or to crash a resource (such as a process, service, or network listener) as a means of denying access to the resource. A new and emerging type of denial-of-service is the distributed denial-ofservice (DDoS) attack, which leverages significant numbers of Internet or networked systems, in an organized manner, to affect a multisystem denial-of-service against a system or network. Many organized DDoS exploits leverage application or other system vulnerabilities to gain system access to a set of vulnerable "slave" systems, which are managed from multiple masters; a covert communications channel is often established between the master and slave and is used to issue instructions to the slave systems. At the attacker's designation, a DDoS attack is launched against the target network using packet flooding or malformed packets to launch the attack.

Thats all guys. Have a nice day.