Now that global law firm DLA Piper is for the most part back up and running after days without phones and email following a massive cyberattack, the financial and business threat to law firms is clear­—as is the need for good cyber insurance.

The malicious software that caused the widespread outage at DLA Piper, and a host of other well-known companies, including one computer at Baker McKenzie’s Kiev office, locked users out of their computers and asked for a $300 ransom payment. Although DLA Piper said it had no evidence that confidential information had been breached, the firm’s web blackout has constrained lawyers and required them to request deadline extensions in court cases. According to some reports, lawyers in some offices are still struggling with the effects of the cyberattack, experiencing limited access to emails and documents.