An example of a phishing email, disguised as an official email from a (fictional) bank. The sender is attempting to trick the recipient into revealing confidential information by "confirming" it at the phisher's website. Note the misspelling of the words received and discrepancy as recieved and discrepency, respectively.
Phishing is a type of social engineering where an attacker sends a fraudulent ("spoofed") message designed to trick a human victim into revealing sensitive information to the attacker or to deploy malicious software on the victim's infrastructure like ransomware. Phishing attacks have become increasingly sophisticated and often transparently mirror the site being targeted, allowing the attacker to observe everything while the victim is navigating the site, and transverse any additional security boundaries with the victim. As of 2020, phishing is by far the most common attack performed by cyber-criminals, with the FBI's Internet Crime Complaint Centre recording over twice as many incidents of phishing than any other type of computer crime.
The first recorded use of the term "phishing" was in the cracking toolkit AOHell created by Koceilah Rekouche in 1995, however it is possible that the term was used before this in a print edition of the hacker magazine 2600. The word is a leetspeak variant of fishing (ph is a common replacement for f), probably influenced by phreaking, and alludes to the use of increasingly sophisticated lures to "fish" for users' sensitive information.
Attempts to prevent or mitigate the impact of phishing incidents include legislation, user training, public awareness, and technical security measures.
Most phishing messages are delivered by email, and are not personalized or targeted to a specific individual or company–this is termed "bulk" phishing. The content of a bulk phishing message varies widely depending on the goal of the attacker–common targets for impersonation include banks and financial services, email and cloud productivity providers, and streaming services. Attackers may use the credentials obtained to directly steal money from a victim, although compromised accounts are often used instead as a jumping-off point to perform other attacks, such as the theft of proprietary information, the installation of malware, or the spear phishing of other people within the target's organization. Compromised streaming service accounts are usually sold directly to consumers on darknet markets.
Spear phishing involves an attacker directly targeting a specific organization or person with tailored phishing emails. In contrast to bulk phishing, spear phishing attackers often gather and use personal information about their target to increase their probability of success of the attack. Spear phishing typically targets executives or those that work in financial departments that have access to the organization's sensitive financial data and services. A 2019 study showed that accountancy and audit firms are frequent targets for spear phishing owing to their employees' access to information that could be valuable to criminals. 
Whaling refers to spear phishing attacks directed specifically at senior executives and other high-profile targets. The content will be likely crafted to be of interest to the person or role targeted - such as a subpoena or customer complaint.
CEO fraud is effectively the opposite of whaling; it involves the crafting of spoofed emails purportedly from senior executives with the intention of getting other employees at an organization to perform a specific action, usually the wiring of money to an offshore account. While CEO fraud has a reasonably low success rate, criminals can gain very large sums of money from the few attempts that do succeed. There have been multiple instances of organizations losing tens of millions of dollars to such attacks.
Clone phishing is a type of phishing attack whereby a legitimate, and previously delivered email containing an attachment or link has had its content and recipient address(es) taken and used to create an almost identical or cloned email. The attachment or link within the email is replaced with a malicious version and then sent from an email address spoofed to appear to come from the original sender. It may claim to be a resend of the original or an updated version to the original. Typically this requires either the sender or recipient to have been previously hacked for the malicious third party to obtain the legitimate email.
Voice phishing, or vishing, is the use of telephony (often Voice over IP telephony) to conduct phishing attacks. Attackers will dial a large quantity of telephone numbers and play automated recordings - often made using text to speech synthesizers - that make false claims of fraudulent activity on the victim's bank accounts or credit cards. The calling phone number will be spoofed to show the real number of the bank or institution impersonated. The victim is then directed to call a number controlled by the attackers, which will either automatically prompt them to enter sensitive information in order to "resolve" the supposed fraud, or connect them to a live person who will attempt to use social engineering to obtain information. Voice phishing capitalizes on the lower awareness among the general public of techniques such as caller ID spoofing and automated dialing, compared to the equivalents for email phishing, and thereby the inherent trust that many people have in voice telephony.
SMS phishing or smishing is conceptually similar to email phishing, except attackers use cell phone text messages to deliver the 'bait'. Smishing attacks typically invite the user to click a link, call a phone number, or contact an email address provided by the attacker via SMS message. The victim is then invited to provide their private data; often, credentials to other websites or services. Furthermore, due to the nature of mobile browsers, URLs may not be fully displayed; this may make it more difficult to identify an illegitimate logon page. As the mobile phone market is now saturated with smartphones which all have fast internet connectivity, a malicious link sent via SMS can yield the same result as it would if sent via email. Smishing messages may come from telephone numbers that are in a strange or unexpected format.
Page hijacking involves compromising legitimate web pages in order to redirect users to a malicious website or an exploit kit via cross site scripting. A hacker may compromise a website and insert an exploit kit such as MPack in order to compromise legitimate users who visit the now compromised web server. One of the simplest forms of page hijacking involves altering a webpage to contain a malicious inline frame which can allow an exploit kit to load. Page hijacking is frequently used in tandem with a watering hole attack on corporate entities in order to compromise targets.
Most types of phishing use some form of technical deception designed to make a link in an email appear to belong to the organization the attackers are impersonating.Misspelled URLs or the use of subdomains are common tricks used by phishers. In the following example URL, http://www.yourbank.example.com/, it can appear to the untrained eye as though the URL will take the user to the example section of the yourbank website; actually this URL points to the "yourbank" (i.e. phishing) section of the example website. Another common trick is to make the displayed text for a link suggest a reliable destination, when the link actually goes to the phishers' site. Many desktop email clients and web browsers will show a link's target URL in the status bar while hovering the mouse over it. This behavior, however, may in some circumstances be overridden by the phisher. Equivalent mobile apps generally do not have this preview feature.
Internationalized domain names (IDNs) can be exploited via IDN spoofing or homograph attacks, to create web addresses visually identical to a legitimate site, that lead instead to malicious version. Phishers have taken advantage of a similar risk, using open URL redirectors on the websites of trusted organizations to disguise malicious URLs with a trusted domain. Even digital certificates do not solve this problem because it is quite possible for a phisher to purchase a valid certificate and subsequently change content to spoof a genuine website, or, to host the phish site without SSL at all.
Phishers have sometimes used images instead of text to make it harder for anti-phishing filters to detect the text commonly used in phishing emails. In response, more sophisticated anti-phishing filters are able to recover hidden text in images using optical character recognition (OCR).
Most types of phishing involve some kind of social engineering, in which users are psychologically manipulated into performing an action such as clicking a link, opening an attachment, or divulging confidential information. In addition to the obvious impersonation of a trusted entity, most phishing involves the creation of a sense of urgency - attackers claim that accounts will be shut down or seized unless the victim takes an action.
An alternative technique to impersonation-based phishing is the use of fake news articles designed to provoke outrage, causing the victim to click a link without properly considering where it could lead. Once on the attacker's website, victims can be presented with imitation "virus" notifications or redirected to pages that attempt to exploit web browser vulnerabilities to install malware.
The term "phishing" is said to have been coined by the well known spammer and hacker in the mid-90s, Khan C. Smith. The first recorded mention of the term is found in the hacking tool AOHell (according to its creator), which included a function for attempting to steal the passwords or financial details of America Online users.
Phishing on AOL was closely associated with the warez community that exchanged unlicensed software and the black hat hacking scene that perpetrated credit card fraud and other online crimes. AOL enforcement would detect words used in AOL chat rooms to suspend the accounts of individuals involved in counterfeiting software and trading stolen accounts. The term was used because "<><" is the single most common tag of HTML that was found in all chat transcripts naturally, and as such could not be detected or filtered by AOL staff. The symbol <>< was replaced for any wording that referred to stolen credit cards, accounts, or illegal activity. Since the symbol looked like a fish, and due to the popularity of phreaking it was adapted as "Phishing". AOHell, released in early 1995, was a program designed to hack AOL users by allowing the attacker to pose as an AOL staff member, and send an instant message to a potential victim, asking him to reveal his password. In order to lure the victim into giving up sensitive information, the message might include imperatives such as "verify your account" or "confirm billing information".
Once the victim had revealed the password, the attacker could access and use the victim's account for fraudulent purposes. Both phishing and warezing on AOL generally required custom-written programs, such as AOHell. Phishing became 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". A user using both an AIM account and an AOL account from an ISP simultaneously could phish AOL members with relative impunity as internet AIM accounts could be used by non-AOL internet members and could not be actioned (i.e., reported to AOL TOS department for disciplinary action).[tone]. In late 1995, AOL crackers resorted to phishing for legitimate accounts after AOL brought in measures in late 1995 to prevent using fake, algorithmically generated credit card numbers to open accounts. Eventually, AOL's policy enforcement forced copyright infringement off AOL servers, and AOL promptly deactivate accounts involved in phishing, often before the victims could respond. The shutting down of the warez scene on AOL caused most phishers to leave the service.
The first known phishing attack against a retail bank was reported by The Banker in September 2003.
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 US$929 million. United States businesses lose an estimated US$2 billion per year as their clients become victims.
Phishing is recognized as a fully organized part of the black market. Specializations emerged on a global scale that provided phishing software for payment (thereby outsourcing risk), which were assembled and implemented into phishing campaigns by organized gangs.
In the United Kingdom losses from web banking fraud—mostly from phishing—almost doubled to GB£23.2m in 2005, from GB£12.2m in 2004, while 1 in 20 computer users claimed to have lost out to phishing in 2005.
Banks dispute with customers over phishing losses. The stance adopted by the UK banking body APACS is that "customers must also take sensible precautions ... so that they are not vulnerable to the criminal." Similarly, when the first spate of phishing attacks hit the Irish Republic's banking sector in September 2006, the Bank of Ireland initially refused to cover losses suffered by its customers, although losses to the tune of €113,000 were made good.
Phishers are targeting the customers of banks and online payment services. Emails, supposedly from the Internal Revenue Service, have been used to glean sensitive data from U.S. taxpayers. While the first such examples were sent indiscriminately in the expectation that some would be received by customers of a given bank or service, recent research has shown that phishers may in principle be able to determine which banks potential victims use, and target bogus emails accordingly.
3.6 million adults lost US$3.2 billion in the 12 months ending in August 2007. Microsoft claims these estimates are grossly exaggerated and puts the annual phishing loss in the US at US$60 million.
Attackers who broke into TD Ameritrade's database and took 6.3 million email addresses (though they were not able to obtain social security numbers, account numbers, names, addresses, dates of birth, phone numbers and trading activity) also wanted the account usernames and passwords, so they launched a follow-up spear phishing attack.
The RapidShare file sharing site has been targeted by phishing to obtain a premium account, which removes speed caps on downloads, auto-removal of uploads, waits on downloads, and cool down times between uploads.
Cryptocurrencies such as Bitcoin facilitate the sale of malicious software, making transactions secure and anonymous.
In January 2009, a phishing attack resulted in unauthorized wire transfers of US$1.9 million through Experi-Metal's online banking accounts.
In the third quarter of 2009, the Anti-Phishing Working Group reported receiving 115,370 phishing email reports from consumers with US and China hosting more than 25% of the phishing pages each.
In March 2011, Internal RSA staff were successfully phished, leading to the master keys for all RSA SecureID security tokens being stolen, then subsequently used to break into US defense suppliers.
Chinese phishing campaigns targeted Gmail accounts of highly ranked officials of the United States and South Korean governments and militaries, as well as Chinese political activists.
According to Ghosh, there were "445,004 attacks in 2012 as compared to 258,461 in 2011 and 187,203 in 2010”.
In August 2013, advertising service Outbrain suffered a spear-phishing attack and SEA placed redirects into the websites of The Washington Post, Time, and CNN.
In October 2013, emails purporting to be from American Express were sent to an unknown number of recipients.
In November 2013, 110 million customer and credit card records were stolen from Target customers, through a phished subcontractor account. CEO and IT security staff subsequently fired.
By December 2013, Cryptolocker ransomware had infected 250,000 computers. According to Dell SecureWorks, 0.4% or more of those infected likely agreed to the ransom demand.
In August 2014, the iCloud leaks of celebrity photos was found to be based on phishing e-mails sent to the victims that looked like they came from Apple or Google, warning the victims that their accounts might be compromised and asking for their account details.
In November 2014, phishing attacks on ICANN gained administrative access to the Centralized Zone Data System; also gained was data about users in the system - and access to ICANN's public Governmental Advisory Committee wiki, blog, and whois information portal.
Charles H. Eccleston plead guilty in an attempted spear-phishing when he attempted to infect computers of 80 Department of Energy employees.
In August 2016, the World Anti-Doping Agency reported the receipt of phishing emails sent to users of its database claiming to be official WADA, but consistent with the Russian hacking group Fancy Bear. According to WADA, some of the data the hackers released had been forged.
In 2017, 76% of organizations experienced phishing attacks. Nearly half of information security professionals surveyed said that the rate of attacks increased from 2016.
In the first half of 2017 businesses and residents of Qatar were hit with more than 93,570 phishing events in a three-month span.
A phishing email to Google and Facebook users successfully induced employees into wiring money – to the extent of US$100 million – to overseas bank accounts under the control of a hacker. He has since been arrested by the US Department of Justice.
In August 2017, customers of Amazon faced the Amazon Prime Day phishing attack, when hackers sent out seemingly legitimate deals to customers of Amazon. When Amazon's customers attempted to make purchases using the "deals", the transaction would not be completed, prompting the retailer's customers to input data that could be compromised and stolen.
In 2018, the company block.one, which developed the EOS.IO blockchain, was attacked by a phishing group who sent phishing emails to all customers, aimed at intercepting the user's cryptocurrency wallet key; and a later attack targeted airdrop tokens.
In 2020, KTH Royal Institute of Technology conducted a study on Why Phishing Still Works?. In this experiment, eight spoofed versions of popular websites and nine legitimate websites were prepared. Then these 17 pages were presented in a random order and users with various technical background and experience were asked to decide if the page they are looking at is a spoofed or legitimate one. In short, people had a hard time figuring out which ones are real and which are fake. Only by looking at the page design and other cosmetic features people got more wrongs than rights. The best strategy was to look at the site URL in combination with the security indicators built into the browser.
Total number of unique phishing reports (campaigns) received, according to APWG
There are anti-phishing websites which publish exact messages that have been recently circulating the internet, such as FraudWatch International and Millersmiles. Such sites often provide specific details about the particular messages.
As recently as 2007, the adoption of anti-phishing strategies by businesses needing to protect personal and financial information was low. Now there are several different techniques to combat phishing, including legislation and technology created specifically to protect against phishing. These techniques include steps that can be taken by individuals, as well as by organizations. Phone, web site, and email phishing can now be reported to authorities, as described below.
Frame of an animation by the U.S. Federal Trade Commission intended to educate citizens about phishing tactics.
People can be trained to recognize phishing attempts, and to deal with them through a variety of approaches. Such education can be effective, especially where training emphasizes conceptual knowledge and provides direct feedback.
Many organizations run regular simulated phishing campaigns targeting their staff to measure the effectiveness of their training.
People can take steps to avoid phishing attempts by slightly modifying their browsing habits. When contacted about an account needing to be "verified" (or any other topic used by phishers), it is a sensible precaution to contact the company from which the email apparently originates to check that the email is legitimate. Alternatively, the address that the individual knows is the company's genuine website can be typed into the address bar of the browser, rather than trusting any hyperlinks in the suspected phishing message.
Nearly all legitimate e-mail messages from companies to their customers contain an item of information that is not readily available to phishers. Some companies, for example PayPal, always address their customers by their username in emails, so if an email addresses the recipient in a generic fashion ("Dear PayPal customer") it is likely to be an attempt at phishing. Furthermore, PayPal offers various methods to determine spoof emails and advises users to forward suspicious emails to their spoof@PayPal.com domain to investigate and warn other customers. However it is unsafe to assume that the presence of personal information alone guarantees that a message is legitimate, and some studies have shown that the presence of personal information does not significantly affect the success rate of phishing attacks; which suggests that most people do not pay attention to such details.
Emails from banks and credit card companies often include partial account numbers. However, recent research has shown that the public do not typically distinguish between the first few digits and the last few digits of an account number—a significant problem since the first few digits are often the same for all clients of a financial institution.
An approach introduced in mid-2006 involves switching to a special DNS service that filters out known phishing domains: this will work with any browser, and is similar in principle to using a hosts file to block web adverts.
To mitigate the problem of phishing sites impersonating a victim site by embedding its images (such as logos), several site owners have altered the images to send a message to the visitor that a site may be fraudulent. The image may be moved to a new filename and the original permanently replaced, or a server can detect that the image was not requested as part of normal browsing, and instead send a warning image.
The Bank of America website is one of several that asks users to select a personal image (marketed as SiteKey) and displays this user-selected image with any forms that request a password. Users of the bank's online services are instructed to enter a password only when they see the image they selected. However, several studies suggest that few users refrain from entering their passwords when images are absent. In addition, this feature (like other forms of two-factor authentication) is susceptible to other attacks, such as those suffered by Scandinavian bank Nordea in late 2005, and Citibank in 2006.
A similar system, in which an automatically generated "Identity Cue" consisting of a colored word within a colored box is displayed to each website user, is in use at other financial institutions.
Security skins are a related technique that involves overlaying a user-selected image onto the login form as a visual cue that the form is legitimate. Unlike the website-based image schemes, however, the image itself is shared only between the user and the browser, and not between the user and the website. The scheme also relies on a mutual authentication protocol, which makes it less vulnerable to attacks that affect user-only authentication schemes.
Still another technique relies on a dynamic grid of images that is different for each login attempt. The user must identify the pictures that fit their pre-chosen categories (such as dogs, cars and flowers). Only after they have correctly identified the pictures that fit their categories are they allowed to enter their alphanumeric password to complete the login. Unlike the static images used on the Bank of America website, a dynamic image-based authentication method creates a one-time passcode for the login, requires active participation from the user, and is very difficult for a phishing website to correctly replicate because it would need to display a different grid of randomly generated images that includes the user's secret categories.
Several companies offer banks and other organizations likely to suffer from phishing scams round-the-clock services to monitor, analyze and assist in shutting down phishing websites. Automated detection of phishing content is still below accepted levels for direct action, with content-based analysis reaching between 80 and 90% of success so most of the tools include manual steps to certify the detection and authorize the response. Individuals can contribute by reporting phishing to both volunteer and industry groups, such as cyscon or PhishTank. Phishing web pages and emails can be reported to Google.
Organizations can implement two factor or multi-factor authentication (MFA), which requires a user to use at least 2 factors when logging in. (For example, a user must both present a smart card and a password). This mitigates some risk, in the event of a successful phishing attack, the stolen password on its own cannot be reused to further breach the protected system. However, there are several attack methods which can defeat many of the typical systems. MFA schemes such as WebAuthn address this issue by design.
Organizations that prioritize security over convenience can require users of its computers to use an email client that redacts URLs from email messages, thus making it impossible for the reader of the email to click on a link, or even copy a URL. While this may result in an inconvenience, it does almost completely eliminate email phishing attacks.
An article in Forbes in August 2014 argues that the reason phishing problems persist even after a decade of anti-phishing technologies being sold is that phishing is "a technological medium to exploit human weaknesses" and that technology cannot fully compensate for human weaknesses.
On January 26, 2004, the U.S. Federal Trade Commission filed the first lawsuit against a suspected phisher. The defendant, a Californian teenager, allegedly created a webpage designed to look like the America Online website, and used it to steal credit card information. Other countries have followed this lead by tracing and arresting phishers. A phishing kingpin, Valdir Paulo de Almeida, was arrested in Brazil for leading one of the largest phishing crime rings, which in two years stole between US$18 million and US$37 million. UK authorities jailed two men in June 2005 for their role in a phishing scam, in a case connected to the U.S. Secret Service Operation Firewall, which targeted notorious "carder" websites. In 2006 eight people were arrested by Japanese police on suspicion of phishing fraud by creating bogus Yahoo Japan Web sites, netting themselves ¥100 million (US$870,000). The arrests continued in 2006 with the FBI Operation Cardkeeper detaining a gang of sixteen in the U.S. and Europe.
In the United States, SenatorPatrick Leahy introduced the Anti-Phishing Act of 2005 in Congress on March 1, 2005. This bill, if it had been enacted into law, would have subjected criminals who created fake web sites and sent bogus emails in order to defraud consumers to fines of up to US$250,000 and prison terms of up to five years.
The UK strengthened its legal arsenal against phishing with the Fraud Act 2006, which introduces a general offence of fraud that can carry up to a ten-year prison sentence, and prohibits the development or possession of phishing kits with intent to commit fraud.
Companies have 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 obtaining passwords and confidential information. March 2005 also saw a partnership between Microsoft and the Australian government teaching law enforcement officials how to combat various cyber crimes, including phishing. Microsoft announced a planned further 100 lawsuits outside the U.S. in March 2006, followed by the commencement, as of November 2006, of 129 lawsuits mixing criminal and civil actions.AOL reinforced its efforts against phishing in early 2006 with three lawsuits seeking a total of US$18 million under the 2005 amendments to the Virginia Computer Crimes Act, and Earthlink has joined in by helping to identify six men subsequently charged with phishing fraud in Connecticut.
In January 2007, Jeffrey Brett Goodin of California became the first defendant convicted by a jury under the provisions of the CAN-SPAM Act of 2003. He was found guilty of sending thousands of emails to America Online users, while posing as AOL's billing department, which prompted customers to submit personal and credit card information. Facing a possible 101 years in prison for the CAN-SPAM violation and ten other counts including wire fraud, the unauthorized use of credit cards, and the misuse of AOL's trademark, he was sentenced to serve 70 months. Goodin had been in custody since failing to appear for an earlier court hearing and began serving his prison term immediately.
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