Instant messaging worms propagation simulation and countermeasures

Abstract

Instant messaging (IM) has become one of the most popular online communication tools among consumer and enterprise IM users. It provides instant message delivery, as well as convenient file transfer services. The increasing popularity and functionalities of IM programs have made it increasingly attractive for attackers, especially for worm writers. IM contact list offers worm an easy way of finding potential victims so that the worm could achieve a surprising spreading speed. This paper first presents our experimental results of simulating IM worm propagation in the logical network defined by IM contact lists, which is reported to be a scale-free network. Then, the existing proposals for detecting and containing IM worm epidemics are discussed. At last, a new algorithm for this purpose is presented, which is based on the observation of the bi-directional nature of IM worm traffic, and its advantages and possible improvements in implementation are analyzed. The simulation results show the proposed algorithm is of significant effect on restricting IM worm propagation. Instant messaging has grown at a phenomenal rate in the last several years to become a major form of communication both over the Internet and within company intranets. As one of the most successful and widely-deployed applications on the Internet, IM has increasingly become the target for attackers to propagate IM-borne viruses, worms, spam over IM (SPIM), malware and phishing attacks. Though widespread in adoption, IM is generally unprotected and unmonitored in consumer and enterprises environment, leaving it vulnerable to attacks and exploits. In 2005, real-time security threats associated with instant messaging, peer-to-peer and other real-time communication technologies increased 1 693% over 2004, with a total of over 2 400 unique threats. IM worms are the most prevalent form of IM malware, representing 90% of all unique attacks in 2005 [1] . These attacks frequently utilized social engineering techniques to lure end users into clicking on suspicious links embedded inside IM messages, enabling the activation of malicious code that compromised the security of host operating systems or applications. In addition, because each user generally has a list of "buddies", it is easy for the worm or virus to find new users and machines to infect. This means that IM worms have the potential to spread very quickly [2] .IM worms are worms that spread in IM networks,by

A review of crude oil emulsification and multiphase flows in chemical flooding

“…Traditional seepage mechanics are based on the continuum hypothesis and Darcy equation, and they play an important role in the development of conventional oil and gas resources 1 . Oil fields with high water cuts account for approximately 70% of China's oil reserves and production, making them the most important part of China's oil production 2 . Chemical flooding is an important method used to enhance oil recovery from these oilfields.…”

“…1 Oil fields with high water cuts account for approximately 70% of China's oil reserves and production, making them the most important part of China's oil production. 2 Chemical flooding is an important method used to enhance oil recovery from these oilfields. One method is to add chemical agents including polymers, surfactants, and alkalis to displace crude oil.…”