By John McCormick, Sara Castellanos and Jared Council

There's always plenty for companies' cybersecurity leaders to worry about, but these days it's different. The coronavirus pandemic has heightened cybersecurity concerns and shifted executives' priorities.

We asked several what's keeping them awake at night. Here are their responses.

Vittorio Cretella

Chief information officer, Procter & Gamble Co.

"The increase of online shopping during the pandemic has been matched by an increase of cybercrime activity. We have seen an increase in attacks targeting our online services, consumers, customers and employees. Threat actors have leveraged Covid-19 messaging and advertisements to increase the effectiveness of their attacks....We have to be relentless about increasing our cyber capabilities -- including advanced threat detection and penetration testing -- to provide additional protection from malware, internet-based attacks, phishing email and other threats."

Jim Fowler

Chief technology officer, Nationwide Mutual Insurance Co.

"Protecting our customers' data with such a distributed workforce has risen to the top of our cybersecurity risks. The pandemic shifted 98% of our 28,000 associates to their homes in three days. Looking into the future, as much as 50% of our associates may end up working from home permanently. We've done an amazing job remaining vigilant so far, but we can't rest. We've been on a five-year journey to replace all our transactional IT systems."

Patrick Foxhoven

Chief information officer, Zscaler Inc.

"By moving so many employees to full-time work from home, there are more opportunities for hackers to try to infiltrate the network....Then there's the unknown affecting employees' abilities to perform their jobs....I also worry about keeping up with the hiring pace. We're in a hypercompetitive market right now for great talent, but people are worried about job security. It's making it a lot harder to bring in the best and the brightest when they are waiting to see what happens in a post-Covid world."

Rick Stark

Chief information officer, CrowdStrike Holdings Inc.

"Enabling a remote workforce securely is top of mind for every CIO right now....Organizations must ensure that they have the best security posture possible by having a cybersecurity policy in place that includes remote working, a plan for employees that includes BYOD, that sensitive data may only be accessed via secure channels and that they have visibility into all devices connecting to the network. Also, it is imperative that employees are educated on the company's security practices, how to avoid scams like phishing and how to communicate and report suspicious activity."

Olivier Leonetti

Chief information officer and chief financial officer, Zebra Technologies Corp.

"In the wake of Covid-19, attackers are taking advantage of the increase in remote workers and are preying on the fear of individuals with Covid-themed scams....In addition to adjusting some of our security protocols, we have also accelerated some of our security road map plans. This includes many practices, from increased software updates, to employee training and awareness, to implementing a zero-trust security model [which requires verification each time anyone seeks access to a network, with no exceptions]....Whether our employees are working from the office, their home or the local coffee shop, you need to make sure the devices are safe and updated for ongoing threats."

Jim Routh

Head of enterprise information risk management, Massachusetts Mutual Life Insurance Co.

"My top concern is reduction of the attack surface for the enterprise -- the combined points where an unauthorized user can try to enter or extract data from a company -- through the elimination of Social Security numbers as a unique identifier and authenticator. This attack surface, which we aim to keep as small as possible as part of basic security protocol, is increased by employees when working from home."

Claus Moldt

Chief technology officer, Fair Isaac Corp.

"We're seeing a spike in fraud and online scams in response to Covid-19. With consumers relying so heavily on online services for banking, we are concerned that they aren't doing enough to protect themselves online....There is an opportunity for banks to help by offering alternative security options to username/password, such as biometrics. We see this as the next frontier for consumer protection, as 78% of consumers would be happy to use behavioral biometrics and 65% are happy to provide physical biometrics including fingerprint scans to secure their online accounts."

Shankar Arumugavelu

Global chief information officer, Verizon Communications Inc.

"The three things that keep me up at night are credential thefts using phishing attacks and malware, the threat of social-engineering attacks to manipulate customers and employees into divulging confidential or personal information, and third-party risk management to prevent malicious actors from infiltrating our network via our partners' systems."

Mr. McCormick is deputy editor of WSJ Pro Artificial Intelligence. Ms. Castellanos is a reporter at The Wall Street Journal's CIO Journal. Mr. Council is a reporter at WSJ Pro Artificial Intelligence. They can be reached at john.mccormick@wsj.com, sara.castellanos@wsj.com and jared.council@wsj.com.