Former colleagues and pals keep 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 group misplaced one in every 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 contemporary ransomware and included a tenure as ESET Senior Analysis Fellow till his retirement in 2018.
With a tutorial background in trendy languages, social sciences, and laptop science, David understood early that essentially the most harmful vulnerabilities weren’t at all times technical, however human. This lesson would echo by way of a lot of his later work, significantly in his writings concerning the psychology of cybercrime. His experience ranged broadly, nonetheless, 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 possibility 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.
When you ever had the privilege of studying from David, contemplate paying it ahead. David himself was proud to be a part of the cybersecurity group and considered cybersecurity as a public good. (He was additionally an achieved singer, songwriter, and guitarist. Hear for your self right here.)
Former colleagues, in the meantime, keep in mind David as a fountain of information and a meticulous wordsmith who left an enduring mark on the sector and all those that labored with him.
Says ESET Vice President of Authorities Affairs Andrew Lee:
“In 1999 I met a person who would turn into a buddy, a colleague, and a collaborator on many tasks over time.
On the time, I used to be working in a authorities workplace, establishing the primary totally applied safety and antivirus platform all through the company. There was a message board, the alt.comp.virus newsgroup (type 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 value studying. He, amongst others, helped me tremendously in offering info and recommendation that helped me do my job.
At a convention known 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 an excellent author, so I requested him for some suggestions. 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 means, I converse much better than I write. David nearly instantly provided to assist me write the paper, and we ultimately offered 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’d 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 would by no means have had the possibility to fulfill the ESET people. David and I stored in contact, often assembly up at trade 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, one in every 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 achieved guitarist, singer, and songwriter. Through the pandemic, I helped him clear up, remix, and grasp a few of his earlier work, and it is a disgrace that extra folks didn’t uncover his songs, as they’re lovely, nicely written, and infrequently deeply transferring.
David was a quiet man, he was light, type, but in addition humorous and intelligent. His work was essential, and whereas the trade has moved on, a lot of the recommendation he wrote remains to be related and important right this moment. His reserved nature generally 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 commonly mentioned, two heads are higher than one. I’ll at all times keep 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 buddy. I’ll miss him drastically.
My like to Jude, David’s daughter, and all who knew and beloved him.
Relaxation in peace my buddy.”
Says ESET Analysis Fellow Bruce P. Burrell:
“I am not fairly certain once I first met David – most likely 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 perhaps 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 outdated buddy.
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 turned 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 nearly all the 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 abilities have been superlative, so it was largely 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 cute eight-to-ten-year-old(?) daughter Katie. I consider that she adopted her father into laptop safety; whether or not or not she’s nonetheless in that discipline, he had each motive to be happy with her.
Over time, we might 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 amazing pleasure – and studying expertise – to work with these two every day, as an alternative 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 actually sooner than I would have preferred it to be!
Submit-retirement, we stayed in contact, however on reflection, not almost 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 can 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 many others. Many individuals know that for all his brilliance as a author and editor, he was ‘clumsy’ as a presenter. Usually dropping monitor, having his notes within the unsuitable order so he was speaking about slides but to come back however not the present one, laughing about his personal errors … Everyone who actually knew him will keep in mind, ‘Oh pricey …’, which was his typical means of apologizing on stage whereas presenting and but once more dropping monitor. But, as a result of his huge information 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 …
Could his reminiscence stay on by way of the music and moments we shared.”
We provide our heartfelt condolences to David’s household and pals.
Right here’s the place you may be taught extra concerning the life and work of David Harley:
