Russian cybersecurity firm Kaspersky says it has unearthed an online group of hackers that it claims has been targeting law firms for the best part of a decade.

The group, called the Deceptikons APT, is also described by Kaspersky in a webinar briefing note as having targeted a set of European law firms last year with spearphishing attempts.

"In all likelihood," the briefing said, "the group's motivations included obtaining specific financial information, details of negotiations, and perhaps even evidence of the law firms' clientele."

The Deceptikons attempted to infiltrate law firms by deploying malicious PowerShell scripts to infect hosts, according to Kaspersky.

The briefing described the Deceptikons as being a "clever, rather than technically advanced" organisation, but added that "it is also highly persistent".

The comments come amid complaints from U.K. law firm IT security heads who say phishing attacks on law firms have rocketed during the lockdown.

Attempts have increased by up to 70% according to estimates by Eversheds Sutherland, which is running mock attacks in order to improve its systems.

"It has become absolutely paramount to have training programs," said William Jenkins, an IT director at the firm.

Another law firm said phishing attempts were "massively up" in the field of electronic signatures.

Henry Trevelyan Thomas, head of customer success at cybersecurity firm Tessian, added that the increased attacks were an issue because "people are less likely to follow safe data practices at home" and because "more and more sensitive conversations are having to happen over written form," which increases the security risk.

In May, the Solicitors Regulation Authority reported that four elite U.S. firms had been targeted by scammers since the start of the coronavirus crisis.

In November, the regulator said during a conference that more than £4 million was stolen from 23 law firms by cybercriminals in the past three years.