Phishing

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This phishing attempt, disguised as an official email from a (fictional) bank, attempts to trick the bank's members into giving away their account information by "confirming" it at the phisher's linked website.

In computing, phishing is a form of criminal activity using social engineering techniques. It is characterized by attempts to fraudulently acquire sensitive information, such as passwords and credit card details, by masquerading as a trustworthy person or business in an apparently official electronic communication. Phishing is typically carried out using email or an instant message, though it has more recently exploited fax. The term phishing derives from password harvesting and the use of increasingly sophisticated lures to "fish" for users' financial information and passwords.

With the growing number of reported phishing incidents, additional methods of protection are needed. Attempts include legislation, user training, and technical measures.

History of phishing

The first recorded mention of phishing is on the alt.2600 hacker newsgroup in January 1996, although the term may have appeared even earlier in the printed edition of the hacker newsletter "2600 Magazine". The term phishing was coined by crackers attempting to "fish" for accounts from unsuspecting AOL members; ph is a common hacker replacement for f.

Early phishing on AOL

Those who would later phish on AOL during the 1990s originally created accounts on AOL with fake, algorithmically generated credit card numbers — these accounts could last weeks or even months until new ones were required. Because AOL eventually brought in measures in late 1995 to prevent this, early AOL crackers resorted to phishing for legitimate AOL accounts.

Phishing on AOL was closely associated with the warez community that exchanged pirated software. A cracker might pose as an AOL staff member and send an instant message to a potential victim, asking the victim to reveal his or her password^[1]. In order to lure the victim into giving up sensitive information the message might include text such as "verify your account" or "confirm billing information". Once the victim had submitted his or her password, the attacker could then access the victim's account and use it for various criminal purposes, such as spamming. Both phishing and warezing on AOL generally required custom-written programs, such as the colorfully named AOHell.

In 1997, AOL's policy enforcement with respect to phishing and warez became stricter and forced pirated software off AOL servers. Around the same time phishing was so prevalent on AOL that they added a line on all instant messages stating: "no one working at AOL will ask for your password or billing information". AOL simultaneously developed a system to quickly deactivate any account involved in phishing, often before their phishes (a term for the victims of a "phish") could respond. Phishers temporarily moved to AOL Instant Messenger (AIM), since they could not be banned from the AIM server. The shutting down of the warez scene on AOL caused most phishers to leave the service, and many phishers — often young teens in their heyday — grew out of the habit.

Recent phishing attempts

More recent phishing attempts have started to target the customers of banks and online payment services. While the first such examples were sent indiscriminately in the hope of finding a customer of a given bank or service, recent research has shown that phishers may in principle be able to establish what bank a potential victim has a relationship with, and then send an appropriate spoofed email to this victim^[2]. E-mails supposedly from the Internal Revenue Service have also been used to glean sensitive data from U.S. taxpayers. In general such targeted versions of phishing have been termed spear phishing.

Phishing examples

PayPal phishing example

An example of a phishing email targeted at PayPal users.

In an example PayPal phish (right), spelling mistakes in the email ("no choise but to temporaly suspend your account"), and the presence of an IP address in the link visible in the tooltip under the yellow box ("Click here to verify your account") are both clues that this is a phishing attempt. Another giveaway, as mentioned elsewhere in this article, is the lack of a personalized greeting. "Dear Customer" or some such indicates a mass mailing, though a personal greeting is not a guarantee of legitimacy either.

SouthTrust Bank example

In this second example, targeted at SouthTrust Bank users, the phisher has used an image to make it harder for anti-phishing scanners to detect by scanning for text commonly used in phishing emails.

From: SouthTrust <support_id_99583160@southtrust.com>

To: john.smith@example.com

Subject: SouthTrust Bank: Important Notification

Date: Thu, 16 Jun 2005 23:56:30 -0200 (22:56 BRT)

An image from a phish targeted at SouthTrust bank customers.

Phishing techniques

Most methods of phishing use some form of technical deception designed to make a link in an email appear to belong to the spoofed organization. Misspelled URLs or the use of subdomains are common tricks used by phishers, such as this example URL, http://www.yourbank.com.example.com/. One method of spoofing links used web addresses containing the @ symbol, which were used to include a username and password in a web URL (contrary to the standard^[3]). For example, the link http://www.google.com@members.tripod.com/ might deceive a casual observer into believing that the link will open a page on www.google.com, whereas the link actually directs the browser to a page on members.tripod.com, using a username of www.google.com; were there no such user, the page would open normally. This method has since been closed off in the Mozilla^[4] and Internet Explorer^[5] web browsers, while Opera provides a warning message and the option not to follow the link.

Some phishing scams use javascript commands in order to alter the address bar. This is done either by placing a picture of the legitimate entity's URL over the address bar, or by closing the original address bar and opening a new one containing the legitimate URL.

In another popular method of phishing, an attacker uses a bank or service's own scripts against the victim. These types of attacks (known as cross-site scripting) are particularly problematic, because they direct the user to sign in at their bank or service's own web page, where everything from the web address to the security certificates appears correct. In reality, the link to the website is crafted to carry out the attack, although it is very difficult to spot without specialist knowledge.

A further problem with URLs has been found in the handling of Internationalized domain names (IDN) in web browsers, that might allow visually identical web addresses to lead to different, possibly malicious, websites. Despite the publicity surrounding the flaw, known as IDN spoofing^[6] or a homograph attack^[7], no known phishing attacks have yet taken advantage of it.

Not all phishing attacks require a fake website. In an incident in 2006^[8], messages that claimed to be from a bank told users to dial a phone number regarding a problem with their bank account. Once the phone number was dialed, prompts told users to enter their account numbers and PIN. The number was provided by a Voice over IP provider.

Damage caused by phishing

A chart showing the increase in phishing reports from October 2004 to June 2005.

The damage caused by phishing ranges from loss of access to email to substantial financial loss. This style of identity theft is becoming more popular, because of the ease with which unsuspecting people often divulge personal information to phishers, including credit card numbers and social security numbers. Once this information is acquired, the phishers may use a person's details to create fake accounts in a victim's name, ruin a victim's credit, or even prevent victims from accessing their own accounts.

It is estimated that between May 2004 and May 2005, approximately 1.2 million computer users in the United States suffered losses caused by phishing, totaling approximately $929 million USD. U.S. businesses lose an estimated $2 billion USD a year as their clients become victims.^[9] In the United Kingdom losses from web banking fraud - mostly from phishing - almost doubled to £23.2m in 2005, from £12.2m in 2004^[10], while 1 in 20 users claimed to have lost out to phishing in 2005^[11].

Anti-phishing

There are several different techniques to combat phishing, including legislation and technology created specifically to target phishing.

Social responses

One strategy for combating phishing is to train users to deal with phishing attempts. One newer phishing tactic, which uses phishing emails targeted at a specific company, known as spear phishing, has been harnessed to train users at various locations, including West Point Military Academy. In a June 2004 experiment with spear phishing, 80% of 500 West Point cadets who were sent a fake email were tricked into revealing personal information^[12].

Users who are contacted about an account needing to be "verified" can take steps to avoid phishing attempts, by contacting the company that is the subject of the email to check that the email is legitimate, or by typing in a trusted web address for the company's website into the address bar of their browser, to bypass the link in the suspected phishing message.

Nearly all legitimate email messages from companies to their customers will contain an item of information that is not readily available to phishers. Some companies, including eBay and PayPal, always address their customers by their username in emails, so if an email addresses a user in a generic fashion ("Dear valued eBay member") it is likely to be an attempt at phishing. Banks and credit card companies will often say something like "This message is about your account number XXXXXXXX1234" with all but the last few digits replaced by "X" for security reasons. Therefore, one should always be suspicious if the message does not contains specific personal information. Phishing attempts in early 2006 have used just such highly personalized information, making it unsafe to rely on personal information alone as a sign that a message is legitimate^[13].

The Anti-Phishing Working Group, an industry and law enforcement association, has suggested that conventional phishing techniques could become obsolete in the future as people are increasingly aware of the social engineering techniques used by phishers.^[14] They propose that pharming and other uses of malware will become more common tools for stealing information.

Technical responses

Anti-phishing software is available that may identify phishing contents on websites, act as a toolbar that displays the real domain name for the visited website, or spot phishing attempts in email. Spam filters also help protect users from phishers, because they reduce the number of phishing-related emails that users receive.

Many organizations have introduced a feature called challenge questions, which ask the user for information that should be known only to the user and the bank. Sites have also added verification tools that allow users to see a secret image that the user selected in advance; if the image does not appear, then the site is not legitimate^[15]. This (and other forms of two-way authentication and two-factor authentication) are still susceptible to attack, such as that suffered by Scandinavian bank Nordea in late 2005^[16].

Several companies offer banks and other entities likely to suffer from phishing scams 24/7 services to monitor, analyze and assist in shutting down phishing websites.

Microsoft's new IE7 browser includes a form of anti-phishing technology, in which the user can choose to check whether the site they are visiting is on a list of known phishing sites. This process can be manual or automatic, and if the site is suspect the user is warned although not prevented from visiting it.^[17]

Legal responses

On January 26, 2004, the FTC (Federal Trade Commission) filed the first lawsuit against a suspected phisher. The defendant, a Californian teenager, allegedly created and used a webpage designed to look like the America Online website, so that he could steal credit card numbers^[18]. Europe and Brazil have both followed the lead of the U.S. by tracing and arresting phishers. In late March 2005, a 24-year-old Estonian man was arrested for using a backdoor, installed after victims visited his fake website, which included a keylogger that allowed him to monitor users' typing ^[19]. Likewise, authorities later arrested a phishing kingpin, Valdir Paulo de Almeida, for leading one of the largest phishing crime rings, which in 2 years stole between $18 and $37 million USD ^[20]. UK authorities jailed two men in June 2005 for their role in a phishing scam ^[21], in a case connected to the USSS Operation Firewall, which targeted notorious "carder" websites ^[22].

In the United States, Democrat Senator Patrick Leahy introduced the Anti-Phishing Act of 2005 on March 1, 2005. The federal anti-phishing bill proposes that criminals who create fake web sites and spam bogus emails in order to defraud consumers could receive a fine up to $250,000 and receive jail terms of up to five years.^[23]

Microsoft has also joined the effort to crack down on phishing. On March 31, 2005, Microsoft filed 117 federal lawsuits in the U.S. District Court for the Western District of Washington. The lawsuits accuse "John Doe" defendants of using various methods to obtain passwords and confidential information. Microsoft hopes to use these lawsuits to uncover some of the largest phishing operators. March 2005 also saw Microsoft partner with the Australian government to teach law enforcement officials how to combat various cyber crimes, including phishing^[24]. Microsoft announced a planned further 100 lawsuits outside the U.S. in March 2006^[25].

AOL reinforced its efforts against phishing^[26] in early 2006 with three lawsuits^[27] seeking a total of $18 million USD under the 2005 amendments to the Virginia Computer Crimes Act^[28][29].

See also

• Anti-phishing software
• Computer insecurity
• Pharming
• Social engineering

References

External links

• Anti-Phishing Working Group - News about phishing.
• Phishing Scams - A large and growing gallery of examples.
• Bank Safe Online - Advice to UK consumers regarding phishing.
• Know Your Enemy: Phishing - Case study from the Honeynet Project on detailed techniques of a couple of phishers.
• Banking Scam Revealed - A public forensic examination of a phishing attack.
• Online survey tool by MailFrontier - Measures ability of users to distinguish email that is legitimate or "phish".
• FTC Consumer Alert - How not to get hooked by a phishing scam.
• Duke Law & Technology Review - Plugging the "phishing" hole: legislation versus technology.
• Safe Browsing for Enterprise Users - How Enterprises can make web browsing safer by using free software applications.