Four more U.K. law firms have been impersonated in fake emails in the past week, as the most recent wave of scam emails batters the mid-market.

Top 50 U.K. firms Shoosmiths, Mills & Reeve and RPC, and top 100 firm Howard Kennedy, have all been impersonated in email scams since last Tuesday (September 10), according to notices filed on the Solicitors Regulation Authority (SRA) website.

The attacks follow a stream of email scams to have hit major U.K. firms in recent months, including Linklaters, which was hit by scam attacks on three separate occasions, and Clifford Chance, whose U.K. managing partner Michael Bates was impersonated by scammers.