A Trojan, sometimes referred to as a Trojan horse, is non-self-replicating malware (in other words, it does not spread like a virus), that appears to perform a desirable function for the user but instead facilitates unauthorised access to the user's computer system. The term is derived from the Trojan horse story in Greek mythology.A trojan can gather and send personal or security information entered on the infected PC. A Trojan usually gains access to a computer when the user is tricked into opening or running a file they downloaded or received from a seemingly legitimate source.

How do Trojans work?

  • The Trojan sits on your computer unknown to you, recording and transmitting personal information, such as your Internet Banking log in details.
  • The Trojan can request extra information which was never asked for before e.g. codes from your AIB Code Card to log in to Internet Banking
  • Once the Trojan has gathered your Internet Banking log in details the fraudster can now log in and make unauthorised transfers from your bank account


  • AIB NEVER request a code(s) from your code card to log in to Internet Banking
  • DO NOT open or download software/images from an unsolicited email or untrustworthy websites.
  • DO NOT use a computer that you do not trust to log in to your internet banking ie. A computer that is open to easy public access like those in internet cafés
  • Ensure you have up-to-date anti-virus, anti-spyware and firewall software intalled on your computer.


What is a Virus?

A computer virus is a program that attaches itself to another program or data file on your computer in order to spread and reproduce itself without the user(s) knowledge. The effects of these viruses can vary widely depending on what they were designed to do. Some viruses cause little or no damage, while others can be very dangerous.

How do Viruses work?

  • Viruses are designed to hide their presence in legitimate programs or data files.
  • They are usually spread from computer to computer by users who are unaware they are doing so through email attachments, downloading files from the Internet, using infected CDs, USB keys, floppy disks etc.
  • Although some viruses are not dangerous (e.g. harmless pop-up windows or advertisements on your PC), a growing number of more sophisticated and dangerous viruses are becoming more widespread which can lead to the following;

- Loss of data and files

- Reduction in network performance

- Confidential data being passed to an unauthorised third party via email

- Damage to your computer hardware


  • Keep up-to-date genuine anti-virus software installed on your computer. This software can detect and eliminate known viruses after the computer downloads or runs the virus.
  • If you are unsure about which anti-virus package to go for or how to install your chosen anti-virus software please contact a computer expert for assistance.

AIB is a registered business name of Allied Irish Banks, p.l.c. Registered Office: Bankcentre, Ballsbridge, Dublin 4.

Registered in Ireland: Registered No. 24173.

Allied Irish Banks, p.l.c. is regulated by the Central Bank of Ireland.

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