A Ukrainian volunteer hacker group known as the IT Army has claimed responsibility for a cyberattack on Russian internet provider Lovit that disrupted services in Moscow and St. Petersburg for three days.

The attack disrupted online services, including the mobile app used for ticket purchases, but did not affect train schedules, Ukrzaliznytsia said. The railway operator is investigating the incident along with Ukraine’s security services.

Law enforcement agencies in seven African countries arrested over 300 suspected cybercriminals involved in mobile banking, investment and messaging app scams, according to a statement on Monday by Interpol.

Although the arrival date of quantum computers is still unknown, the U.K. NCSC issued new guidance to help organizations transition to cryptographic algorithms and protocols that can protect data threatened by big advances in computing power.

Alphabet said New York-based Wiz will be folded into Google Cloud, a unit that also includes the incident response and threat intelligence subsidiary Mandiant. The deal is subject to review by federal antitrust regulators.

The researchers tied the campaign to the group Storm-1865, which has launched several other phishing campaigns that involve stealing payment data and making fraudulent charges.

A popular set of SCADA software systems used in critical infrastructure around the world suffered from at least five known vulnerabilities that could have allowed for privilege escalation, DLL hijacking and the ability to modify critical files.

A Russian security agency has accused Ukraine of hacking two Kremlin-backed youth military-patriotic organizations to gather student data for potential recruitment in espionage or terrorist activities.

Russian cryptocurrency exchange Garantex was taken down in an apparent seizure by U.S. and European law enforcement Thursday, shortly after the company said $28 million had been frozen by another cryptocurrency firm.

In a white paper published on Wednesday, Microsoft said the cost to mitigate basic cyber risks across all of the approximately 2,100 rural hospitals in the U.S. would be $70 million to $75 million.