The attackers did not steal any data, but the firm had to rebuild its servers to get back into operation, said Albert Rodriguez, a manager at ImageMaster.

"If I wanted to target municipal finance, this would be a really good place for me to start," said Omid Rahmani, public finance cybersecurity lead at Fitch Ratings.

Nevada is the latest public entity to be hit by a cyberattack, with officials struggling to restore services.

St. Paul, Minnesota, is recovering from a cyber attack that overwhelmed the city's defenses ahead of its Aug. 19 bond deal close.

Since the attack, many in the industry have had conversations about how to better secure transfer of funds, Vivian Altman said.

Closing is scheduled for White Lake Township, Michigan's second try at a GO bond sale after the first was interrupted by the cybertheft of bond proceeds.

While the White Lake, Michigan, township hack is the best-known and publicly disclosed cyberattack, there have been others. Some issuers and firms are reluctant to share these experiences publicly.

SEC probe relating to a cyberattack on a Michigan township's bond sale could involve looking into whether investors are getting an accurate picture of the issuer's credit risk, a former SEC enforcement attorney said.

Belvia Gray, Public Finance Leader at Baker Tilly, talks about the firm's efforts and focus on bringing the industry together on cyber security threats, succession planning and more.

The public finance industry is addressing cyber threats, which became clearer with last year's hack of White Lake Township's bond closing.

White Lake Township, Michigan, is facing legal action on two fronts: one of them related to the hack of its bond deal closing last year, the other a civil suit. 

The offering document for a White Lake Township bond sale sheds more light on the hack criminals used to intercept funds between the underwriter and borrower.

It's hard enough convincing local governments to spend money on cyber insurance that covers ransomware attacks, said Omid Rahmani, public finance cybersecurity lead at Fitch Ratings. The new and very specific threat of a hacked financing process, is "absolutely" underappreciated by the public finance industry.

"This matter is now under active investigation by federal authorities and impacted financial institutions, who are coordinating with the White Lake Township Police Department," said Daniel Keller, chief of police, in a statement.

The threat of cybercrime against municipalities continues to mutate into more sophisticated and life-threatening schemes, say economists and rating agencies.

Ransomware group LockBit threatened on Sunday to publish the stolen data Tuesday evening. Ransomware experts said it was likely that the group was bluffing.

With cyberattacks on the rise, issuers have had to keep fortifying their defenses against criminals targeting the public sector. 

While the SEC's cybersecurity rule does not apply to municipal issuers, there are a few points discussed in the Adopting Release that may be useful for municipal market participants. 

New York State Comptroller Thomas DiNapoli urged state agencies to do more to protect water systems from cyberattacks as Moody's Investors Service said cyber risks pose challenges to municipalities across the United States.

Through proposed SEC regulations, federal grants and cybersecurity insurance, areas of the public finance industry are adjusting to costly and omnipresent cyber threats.