Policymakers and analysts in Washington and elsewhere call for development of international rules of cyber conflict ("e-Neva," riffing on "Geneva," as in the Conventions, some infelicitously call it). The Wall Street Journal advises those interested in the coming shape of cyber warfare to look at Ukraine, and how Russia's slow-motion imperial re-engorgement of that country has used cyber operations as a combat multiplier.

The ISIS-inspired "Cyber Caliphate" is back with Twitter hacks in a renewed campaign to avenge its fallen Internet star.

European authorities take down the Iranian Revolutionary Guard's "Rocket Kitten" cyber espionage campaign. Check Point Software, Europol's principal industry partner in the action, offers a long list of Rocket Kitten's targets (which include regional rivals like Saudi Arabia and the UAE, human rights groups, Iranian dissidents, Israel — particularly that country's nuclear R&D, the United States, and even commercial interests in friendly Venezuela).

ProtonMail comes online again, expressing regret for having paid ransom to get the "Armada Collective" DDoS extortionists off its back. Other services the DDoS gang recently hit are said to include Zoho and banks in Switzerland and Thailand.

Extortion is the classic way of monetizing DDoS attacks. It's also the route taken by ransomware operators, who continue to up their game. Some good news, though: Linux.Encoder.1 ransomware turns out, finds Bitdefender, to be relatively easy to break.

In industry news, KEYW stock plummets after the company reports disappointing results. Tenable and Cybric each close new funding rounds.

GCHQ's head says the market is failing cyber security.