Know your Enemy: Phishing

Behind the Scenes of Phishing Attacks
Primary Authors
David Watson: [email protected]
Thorsten Holz: [email protected]
Sven Mueller: [email protected]

Last Modified: 16th May 2005

Phishing is the practice of sending out fake emails, or spam, written to appear as if they have been sent by banks or other reputable organisations, with the intent of luring the recipient into revealing sensitive information such as usernames, passwords, account IDs, ATM PINs or credit card details. Typically, phishing attacks will direct the recipient to a web page designed to mimic a target organisation's own visual identity and to harvest the user's personal information, often leaving the victim unaware of the attack. Obtaining this type of personal data is attractive to blackhats because it allows an attacker to impersonate their victims and make fraudulent financial transactions. Victims often suffer significant financial losses or have their entire identity stolen, usually for criminal purposes. This KYE white paper aims to provide practical information on the practice of phishing and draws on data collected by the German Honeynet Project and UK Honeynet Project. This paper focuses on real world incidents that the Honeynet Project has observed in the wild, but does not cover all possible phishing methods or techniques. Attackers are constantly innovating and advancing, and there are likely to be new phishing techniques already under development or in use today.

After a brief introduction and background, we will review the actual techniques and tools used by phishers, providing three examples of empirical research where real-world phishing attacks were captured using honeynets. These incidents will be described in detail and include system intrusion, phishing web site preparation, message propagation and data collection. Common techniques and trends are then analysed, including the growing integration of phishing, spamming, and botnets. Examples of the malware used by phishers to automate harvesting of email addresses and sending of spam email are reviewed, and we also present our observations on network scanning techniques and how compromised machines are used to spread phishing emails and other spam. Finally, we conclude this paper with an overview of the lessons learned in the last six months and suggest further research topics.

This white paper includes extensive amounts of supporting information, with many hyperlinks to more detailed data on specific attacks available inline. Lastly, no confidential personal data was collected in the process of this research. In some cases, organizations involved in phishing attacks were contacted directly, or the incident data was forward to local CERTs.