A malware attack on Wolters Kluwer, a popular tax and accounting software platform, has left many in the accounting world unable to work this week and sparked concerns about the security of the tax return and financial information stored on the company's cloud servers. One accountant at a large, Midwest-based accounting firm, said that the accounting world was in a "quiet panic" over the attack. But she also said her firm took additional precautions to "limit any possible exposure" to the malware attack through the accounting giant's technology connections to the software company. The accountant from the Midwest-based accounting firm said that data loss was his "primary concern." But he said he'd only received one call from a client asking about data. "I'd characterize it as a bit of a 'quiet panic' right now in the corporate accounting world, without a lot of information," he said. For the clients who need to file by May 15, the accountant said he is coming up with a back-up plan: "Do it by hand."