A prodigious student has caused a stir in the technology world after cracking a malicious virus which affected smartphone users around the world.

Simon Bell, a BSc computer sciences student at the University of Sussex who graduated last week, neutralised a virus called ransomware.

The malicious software remotely locked phones and tablets and demanded a ransom.

For his final-year project Mr Bell created a honeypot – a program that simulates a vulnerable computer, to attract malware and study its behaviour.

He then created a program that decrypts any file encrypted by the programme.

His analysis and antidote were picked up by many specialist news websites.

Professor John Carroll, head of informatics at the university, said: “Apart from analysing techniques used in malware, Simon has also investigated the common steps that hackers make when they attempt to break into an organisation’s computer systems, for example exploiting users’ poor choices of passwords.”

In his blog Mr Bell said: “The antidote for this ransomware was incredibly easy to create because the ransomware came with both the decryption method and the decryption password.

“Therefore producing an antidote was more of a copy-and-paste job than anything.”

He added: “Future versions of advanced smartphone ransomware will likely prove significantly harder to reverse engineer.”