Email is now a very widely used communication method. If an email account is hacked it can allow the attacker access to the personal, sensitive, or confidential information in the mail storage; as well as allowing them to read new incoming and outgoing email - and to send and receive as the legitimate owner. On some email platforms it may also allow them to setup automated email processing rules. All of these could be very harmful for the legitimate user.
Phishing involves emails that appear to be from legitimate sender but are scams which ask for verification of personal information, such as an account number, a password, or a date of birth. If unsuspecting victims respond, the result may be stolen accounts, financial loss, or identity theft.
Email on the internet is sent by the Simple Mail Transfer Protocol (SMTP). While mail can be encrypted between mail servers, this is not typically enforced, but instead Opportunistic TLS is used - where mailservers negotiate for each email connection whether it will be encrypted, and to what standard. Where a mail flow between servers is not encrypted, it could be intercepted by an ISP or government agency and the contents can be read by passive monitoring. For higher security, email administrators can configure servers to require encryption to specified servers or domains.
Email spoofing and similar issues which facilitate phishing are addressed by the 'stack' of Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM) and Domain-based Message Authentication, Reporting and Conformance (DMARC). Setting all these in place is technically challenging, and not visible to the end user, so implementation progress has been slow. A further layer, Authenticated Received Chain (ARC), allows mail flow through intermediate mail servers such as mailing lists or forwarding services to be better handled - a common objection to implementation.
Businesses typically have advanced firewalls, anti-virus software and intrusion detection systems (IDS) to prevent or detect improper network access. They may also have security specialists perform an audit on the company and hire a Certified Ethical Hacker to perform a simulated attack or "pen test" in order to find any gaps in security.
Although companies may secure its internal networks, vulnerabilities can also occur through home networking. Email may be protected by methods, such as, creating a strong password, encrypting its contents, or using a digital signature.
If passwords are leaked or otherwise become known to an attacker, having two-factor authentication enabled may prevent improper access.
Cases of email hacking
Notable cases of email hacks include:
- Email archives from the Climatic Research Unit were leaked to create the scandal popularly known as Climategate.
- News of the World journalists hacked email accounts for their stories.
- UK politician Rowenna Davis had her mail account taken over and held ransom.
- US politician Sarah Palin has been hacked in order to find embarrassing or incriminating correspondence.
- As part of the Sony Pictures hack, over 170,000 pieces of email between top executives ended up on Wikileaks.
- Former United States president, George H.W. Bush had his email hacked.
- The personal email of political consultant John Podesta was hacked, and contents later published by WikiLeaks.
- Joel Scambray; Stuart McClure; George Kurtz (2001), "Email Hacking", Hacking Exposed, McGraw-Hill, p. 626, ISBN 9780072127485
- R. Thilagaraj; G Deepak Raj Rao (2011), "Email hacking", Cyber Crime and Digital Disorder, Manonmaniam Sundaranar University, p. 3, ISBN 9789381402191
- Alex Kosachev; Hamid R. Nemati (2009). "Chronicle of a journey: an e-mail bounce back system". International Journal of Information Security and Privacy. 3 (2): 10.
- McCullagh, Declan (21 June 2013). "How Web mail providers leave door open for NSA surveillance". c|net. Retrieved 2 October 2018.
- Nitesh Dhanjani; Billy Rios; Brett Hardin (2009), "Abusing SMTP", Hacking, O'Reilly Media, pp. 77–79, ISBN 9780596154578
- "Online security: Hacking". New Media Age: 8–9. 24 March 2005.
- "All Projects - PRISM Break". prism-break.org.
- Maxwell T. Boykoff (2011), "The UEA CRU email hacking scandal (a.k.a. 'Climategate')", Who Speaks for the Climate?, Cambridge University Press, pp. 34–40, ISBN 9780521133050
- James Cusick; Ian Burrell (20 January 2012), "We hacked emails too – News International", The Independent, London
- Tony Dyhouse (25 October 2011), Email hacking victim Rowenna Davis tells her story, BBC
- Charles P. Pfleeger; Shari Lawrence Pfleeger (2011), Analyzing Computer Security, Prentice Hall, pp. 39–43, ISBN 9780132789462
- Verhoeven, Beatrice (11 November 2015). "Greatest Hits of Leaked Sony Emails". TheWrap. Retrieved 3 October 2018.
- "Hacker exposes ex-US President George H W Bush emails". BBC News. 8 February 2013. Retrieved 10 February 2013.
- Franceschi-Bicchierai, Lorenzo (October 20, 2016). "How Hackers Broke Into John Podesta and Colin Powell's Gmail Accounts". Motherboard. Retrieved August 13, 2018.
- Stein, Jeff. "What 20,000 pages of hacked WikiLeaks emails teach us about Hillary Clinton". Vox. Retrieved October 21, 2016.