Spoofing is a practice whereby the user on the internet attempts to conceal its IP address to conceal its true identity. Many crackers steal databases of credit cards or other sensitive information[1].
The concept of IP spoofing, was initially discussed in academic circles in the 1980’s. While known about for sometime, it was primarily theoretical until Robert Morris,whose son wrote the first Internet Worm,discovered a security weakness in the TCP protocol known as sequence prediction.Stephen Bellovin discussed the problem in-depth in Security Problems in the TCP/IP Protocol Suite, a paper that addressed design problems with the TCP/IP protocol suite. Another infamous attack, Kevin Mitnick’s Christmas Day crack of Tsutomu Shimomura’s machine, employed the IP spoofing and TCP sequence prediction techniques. While the popularity of such cracks has decreased due to the demise of the services they exploited, spoofing can still be used and needs to be addressed by all security administrators[2]. The Buffalo Spammer is a notorious spammer who was accused of sending more than 800 million unsolicited emails from illegal earth link accounts. He also stole credit cards and identities to fraudulently by 343 earth link accounts to send shady and unsolicited mails to different people. On long investigation the identity of this spammer was found to be that of Mr. Howard Carmack who sent out millions of emails that included advertisements for computer virus scripts, software for bulk mailing and list of addresses to be used by other spammers. He was arrested in New York.
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[1]http://www.iss.net/security_center/advice/Underground/Hacking/Methods/Technical/Spoofing/default.htm