CrowdStrike shares tumble as fallout from global tech outage continues

CrowdStrike shares slipped 13% during Monday's trading session, as the cybersecurity software company continued to help clients across industries recover from an outage that took millions of Microsoft Windows devices offline last week.

Early on Friday, the company issued a defective update to its Falcon vulnerability-protection software that caused PCs, computer servers in data centers and display screens to crash, resulting in grounded flights and canceled medical appointments. The incident ensnared 8.5 million Windows devices, less than 1% of the global total, Microsoft said.

IT staffers quickly worked to fix computers. Meanwhile, hackers sought to take advantage of the confusion by setting up malicious websites that appeared to offer software updates. CrowdStrike CEO George Kurtz addressed the situation on air with CNBC's Jim Cramer.

CrowdStrike shares fell 11% on Friday. But then, over the weekend, people shared photos on social media of Windows devices displaying the so-called "blue screen of death," a sign of computers in need of attention from administrators. CrowdStrike said on Sunday that it was testing a method that would fix affected machines more quickly.

Guggenheim Securities downgraded its rating on CrowdStrike shares to neutral from buy on Sunday. Analysts led by John DiFucci said the stock was still trading at "the highest multiple of recurring revenue across our entire software coverage."

It might take time for CrowdStrike to repair its image, and the fallout will probably hurt signings, the analysts wrote. Signings are an early estimate of contract value from new and existing customers that can give investors a sense of a company's potential for revenue generation.

"We still have the utmost respect for the