After a checkered career that included spells in music, bar-work, work with the mentally handicapped, retail and the building trade, Harley entered the IT field in the late 1980s, working initially in administration at the
Royal Free Hospital in London, and in 1989 went to work for the Imperial Cancer Research Fund (now merged into
Cancer Research UK), where he held administrative and IT support roles and eventually moved into full-time security. In 2001, he joined the
National Health Service where he ran the Threat Assessment Centre. After leaving the NHS in 2006 to work as an independent consultant, he worked closely with the security company
ESET where between 2011 and 2018 he held the position of Senior Research Fellow, In 2009, he was elected to the board of directors of the
Anti-Malware Testing Standards Organization (AMTSO). He stood down in February 2012, when Righard Zwienenberg, president of AMTSO, joined ESET, as the AMTSO bylaws don't allow more than one Board member to represent the same AMTSO member entity. He ran the Mac Virus website, and formerly held an undefined executive role in
AVIEN. He is a former Fellow of the
British Computer Society: he explained in a blog article in 2014 that he was dropping his subscriptions to the BCS Institute and
(ISC)2 (and therefore would no longer be entitled to continue using the acronyms
CISSP,
CITP and
FBCS), and his reasons for so doing. In January 2019, he announced that he was no longer working with ESET and was reverting to his former career as a musician, but indicated that he was still available for one-off authoring and editing work. He subsequently contributed content, reviewing and translation for the English edition of the book
Cyberdanger by
Eddy Willems. == Writing ==