[3] 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.
He is a former Fellow of the British Computer Society: he explained in a blog article [12] 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.
[13] He subsequently contributed content, reviewing and translation for the English edition of the book Cyberdanger by Eddy Willems.
[14] Harley was co-author (with Robert Slade and Urs Gattiker) of Viruses Revealed,[15] and technical editor and principal author of The AVIEN Malware Defense Guide for the Enterprise.
[16] He also contributed chapters to a number of other security-related books, and sometimes wrote for specialist security publishers such as Virus Bulletin[17] and Elsevier.