Macfarlanes senior partner Charles Martin has branded the growing danger posed by cyberattacks as an "existential threat" to law firms.

Speaking on a panel at the Global Independent Law Firm Forum yesterday (26 April), Martin (pictured) responded to a question about what kept him awake at night by saying that a cybersecurity breach is "the one thing that could have a dramatic adverse impact on our businesses".

He said his advice to other law firm leaders was to never be afraid of asking cybersecurity experts "dumb questions" or to shy away from challenging them to create a "zero tolerance perspective" when it comes to protecting your firm.

Martin was speaking on a panel of law firm leaders including Cravath Swaine & Moore London managing partner Philip Boeckman, Mannheimer Swartling managing partner Jan Dernestam, and Dimitry Afanasiev, the co-founder of Russian firm Egorov Puginsky Afanasiev & Partners.

Dernestam echoed Martin's warning to firms, adding: "We have all seen the terrible examples of law firms caught in cybersecurity issues."

Last year, DLA Piper was hit by a major cyberattack that saw phones and computers knocked out across the firm. The firm was one of a number of companies to fall victim to the 'Petya' ransomware attack and, at the time, insurance brokers said the resulting upheaval could have have seen the firm incur costs "in the millions".

Afanasiev said that what most concerns him are the issues beyond the control of law firms. He joked: "The risk of nuclear war keeps me awake at night," adding: "It is things like geopolitical ruptures, that we can't control, that keep managing partners awake. They drag with them issues such as a constantly shifting compliance environment."

In a wide-ranging discussion, the panel also discussed the importance of independent law firms having strong links to 'best friend' firms around the world.

Boeckman said: "We all need to think of things globally and we need to be reaching out to our clients and focusing on not only their domestic work, but also their global work. We need to make them aware that we have this global network of fantastic firms."

Martin added: "It is essential for our clients that the international ecosystem of independent firms works together."

The Global Independent Law Firms Forum, which was held at Jumeirah Carlton Tower, was co-chaired by Martin and Wachtell Lipton Rosen & Katz M&A partner Adam Emmerich. Other subjects on the agenda included technology, millennials and new approaches to law firm marketing, with speakers including Harvard Law School's Professor Heidi Gardner, ex-Allen & Overy senior partner David Morley and DLA Piper global co-chair Roger Meltzer.