Former colleagues and associates bear in mind the cybersecurity researcher, writer, and mentor whose work bridged the human and technical sides of safety
07 Nov 2025
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7 min. learn
The cybersecurity neighborhood misplaced considered one of its luminaries with the passing of David Harley final week, on the age of 76.
Regardless of being a self-described late entrant to IT, David went on to forge an extended and distinguished profession in cybersecurity that stretched from the early days of laptop viruses till the age of recent ransomware and included a tenure as ESET Senior Analysis Fellow till his retirement in 2018.
With an instructional background in fashionable languages, social sciences, and laptop science, David understood early that probably the most harmful vulnerabilities weren’t at all times technical, however human. This lesson would echo via a lot of his later work, notably in his writings in regards to the psychology of cybercrime. His experience ranged broadly, nevertheless, and in addition encompassed evaluation of malware tendencies and engagement with the requirements of antimalware product testing.
A prolific writer, editor, and convention speaker, David considered writing and public talking as an extension of analysis and a chance to attach with friends and, certainly, anybody else dedicated to creating the web a safer place for everybody. WeLiveSecurity is proud to protect a part of David’s huge physique of written work; in the meantime, the varied books and scholarly articles that he authored, co-authored, and edited are listed right here.
In case you ever had the privilege of studying from David, contemplate paying it ahead. David himself was proud to be a part of the cybersecurity neighborhood and considered cybersecurity as a public good. (He was additionally an completed singer, songwriter, and guitarist. Hear for your self right here.)
Former colleagues, in the meantime, bear in mind David as a fountain of information and a meticulous wordsmith who left an enduring mark on the sphere and all those that labored with him.
Says ESET Vice President of Authorities Affairs Andrew Lee:
“In 1999 I met a person who would grow to be a pal, a colleague, and a collaborator on many tasks through the years.
On the time, I used to be working in a authorities workplace, establishing the primary absolutely applied safety and antivirus platform all through the company. There was a message board, the alt.comp.virus newsgroup (sort of like a really early social media for geeks), the place others concerned within the antivirus sphere would talk about. On that discussion board, on the time working for the NHS as its laptop safety head, was a person named David Harley. On that board, many conversations would happen, and David would usually give his enter, which was related, knowledgeable, and at all times price studying. He, amongst others, helped me tremendously in offering info and recommendation that helped me do my job.
At a convention referred to as ‘Infosec’ (sadly lengthy defunct), I lastly met David, in late 1999, and we hit it off instantly, sharing many extra pursuits than simply safety. Throughout that first assembly, over pizza, I mentioned an concept that I used to be engaged on – a paper on Linux malware. I knew David was a superb author, so I requested him for some ideas. I’ve at all times been good at having concepts, however with extreme ADHD (undiagnosed on the time), I used to be merely unable to get them onto the web page in a logical manner, I communicate much better than I write. David virtually instantly supplied to assist me write the paper, and we ultimately introduced it on the EICAR convention in 2001, in Copenhagen. I did the presenting, because it was not David’s energy on the time. We complemented one another nicely. We might bounce concepts round, he would ship a draft, I might add my contributions, then he would edit it into one thing usable. Then I would current our work.
Finally, I left authorities and joined ESET – and it is true to say that with out David serving to me with these early convention papers, I’d by no means have had the possibility to fulfill the ESET people. David and I saved in contact, recurrently assembly up at business conferences, and ultimately, it was an enormous pleasure to have the ability to rent him into ESET, the place as soon as once more, we labored on many white papers and displays collectively. He additionally wrote books on safety, considered one of which I had the pleasure of contributing to.
We additionally bonded over music. David was, like me, an enormous fan of conventional British people music, and was himself a really completed guitarist, singer, and songwriter. Throughout the pandemic, I helped him clear up, remix, and grasp a few of his earlier work, and it is a disgrace that extra individuals didn’t uncover his songs, as they’re lovely, nicely written, and sometimes deeply transferring.
David was a quiet man, he was mild, sort, but in addition humorous and intelligent. His work was necessary, and whereas the business has moved on, a lot of the recommendation he wrote continues to be related and very important in the present day. His reserved nature typically hid from others the deep mind and perception that David held.
In some small half, I hope our work collectively helped him too; as is usually mentioned, two heads are higher than one. I’ll at all times bear in mind when he met his true ‘second head’, Jude, in Berlin, and their lasting bond, friendship, and love was one thing that was apparent to those that met them.
Above all, David was my pal. I’ll miss him enormously.
My like to Jude, David’s daughter, and all who knew and beloved him.
Relaxation in peace my pal.”
Says ESET Analysis Fellow Bruce P. Burrell:
“I am not fairly certain once I first met David – in all probability although VIRUS-L/comp.virus within the late 80s or early 90s. I am not sure about once I met him in particular person, both, however I am fairly certain it was in 1995, on the Virus Bulletin convention in Boston. Or possibly in San Francisco at VB 97 (the convention report mentions him, so I do know he was there). Every time it was, by that point it was like assembly an previous pal.
In all probability a bit earlier than our first face-to-face assembly, the alt.comp.virus newsgroup got here into existence, and I had many interactions with David there. Finally, it grew to become clear that an FAQ was wanted for the newsgroup, and a triumvirate of David, George Wenzel, and I began placing one collectively. Extra precisely, David did virtually the entire placing, whereas George and I contributed a bit or two; I additionally did a wee little bit of wordsmithing. Emphasis on ‘wee’: David’s writing expertise had been superlative, so it was principally simply sanity-checking.
Word additionally that, whereas the gentlest and kindest of individuals, he had a wickedly intelligent wit – simply browse the titles and headers of his writings.
I overnighted at his flat in London in the summertime of 1998, and later that yr, at VB 98, I met the common occupant of that room – his lovely eight-to-ten-year-old(?) daughter Katie. I imagine that she adopted her father into laptop safety; whether or not or not she’s nonetheless in that subject, he had each purpose to be pleased with her.
Through the years, we would been in common contact – however once I joined ESET, we quickly shaped one other trio of wordsmiths – David, Nick FitzGerald, and myself. It was an important pleasure – and studying expertise – to work with these two each day, as a substitute of the occasional one-off emails and the all-too-rare convention or ‘I simply occur to be on the town’ conferences. I used to be lucky to have the ability to work with him intently for a number of years, till his retirement. Not an early retirement, however definitely sooner than I would have appreciated it to be!
Put up-retirement, we stayed in contact, however on reflection, not practically sufficient. I shall miss you tremendously.”
Says ESET Senior Analysis Fellow Righard Zwienenberg:
“I’m actually saddened to listen to this information. Having recognized David for over three many years, I used to be lucky to share many memorable moments with him, on stage throughout displays and thru our mutual love of music. We had some good classes along with David on guitar and myself on drums. He shall be deeply missed by me.
David was a ‘strolling Wikipedia’. Everytime you despatched him an summary or a full paper to edit, he at all times returned it with hints to extra materials, references to supporting materials, and so forth. Many individuals know that for all his brilliance as a author and editor, he was ‘clumsy’ as a presenter. Usually shedding observe, having his notes within the flawed order so he was speaking about slides but to return however not the present one, laughing about his personal errors … Everyone who actually knew him will bear in mind, ‘Oh expensive …’, which was his typical manner of apologizing on stage whereas presenting and but once more shedding observe. But, because of his huge data on the subject he was presenting or ready-when-needed historical past when the Q&A time was there, he at all times attracted a big crowd …
Might his reminiscence dwell on via the music and moments we shared.”
We provide our heartfelt condolences to David’s household and associates.
Right here’s the place you’ll be able to study extra in regards to the life and work of David Harley:
