Security experts at Alphabet Inc.'s Google have identified more than a dozen government-backed hacking groups using the COVID-19 pandemic as cover for phishing and malware attempts.

Google said on Wednesday its Threat Analysis Group found hackers targeting international health organizations, including activity corroborating a Reuters report from early April that the World Health Organization was targeted.

WHO and other organizations, at the center of a global effort to contain the coronavirus, have come under a sustained digital bombardment by hackers seeking information about the outbreak.

Google (GOOGL) said it has detected 18 million malware and phishing Gmail messages per day related to the coronavirus outbreak.

"One notable campaign attempted to target personal accounts of U.S. government employees with phishing lures using American fast food franchises and COVID-19 messaging," Google said in a blog post.

Some messages also offered free meals and coupons in response to COVID-19, others suggested recipients visit sites disguised as online ordering and delivery options, according to the blog post.

Google said it was working to identify and prevent threats, using a combination of internal investigative tools, information sharing with industry partners and law enforcement, as well as leads and intelligence from third-party researchers.