A pro-Russian group has claimed responsibility for attacks that floored German government websites on Wednesday, although Ukraine's PM is pointing the figure at Russia itself.
Hacktivists from CyberBerkut1 blockaded the websites of the Bundestag and Chancellor Merkel's office, demanding Berlin end support for the Ukrainian government.
The assault left the sites largely inaccessible from around from 09:00 GMT until early evening.
Assaults against German government websites are a daily occurrence. The severity and duration of Wednesday's assaults were however unusual.
Ukraine's prime minister Arseny Yatseniuk blamed Russian intelligence rather than hacktivists for orchestrating the assault. "I strongly recommend that the Russian secret services stop spending taxpayer money for cyber attacks against the Bundestag and Chancellor Merkel's office," he told ZDF TV, Reuters reports.
Yatsenyuk was due to meet Merkel in Berlin today (8 January), with sanctions against Russia and the ongoing conflict in the east of Ukraine expected to be high on the agenda. Russian state-funded cable and satellite television channel RT argues that CyberBerkut is solely behind the assault, which it attributes to anger at Yatsenyuk's "plans to use billions from the EU to fund war in the east of the country rather than rebuild it".
Attribution for attacks in cyberspace is a difficulty, and the issue is becoming more pressing as the internet is increasingly turning into an arena for sniping between nations.
The idea that the Russian state rather then pro-Russian activists might be behind the assault on German government websites is "possible, plausible & even probable" but this does not equal proven, noted Prof Alan Woodward of the University of Surrey, in a Twitter update.
Chris McIntosh, chief exec of secure communications outfit ViaSat UK, commented: "The fact that Russia’s alleged cyber attack against Germany is supposedly in response to its continued support of the Ukrainian government shows that these attacks are becoming the first weapon of choice for countries in conflict."
"This is further supported by the recent Sony hack, with North Korea taking the blame and subsequent counter-attacks taking down that country’s internet ascribed to the US," he added.
"The lines between private, public and military targets are blurring, and cyber attacks are now being looked to as an effective way of influencing other countries’ foreign policy. In this new landscape of threats, organisations in all sectors will need to be vigilant against a wider range of threats; not only from countries with significant resources at their disposal and the incentives to use them, but also from other actors working in hostile nations’ interests," he concluded.
1Ukraine's former (pro-Russian) president Viktor Yanukovich used "Berkut" riot squads against protesters prior to losing grip on power following violent protests last February. The CyberBerkut name deliberately references Yanukovich's controversial policing force.
The grouping has previously been linked to attacks on NATO websites and US private military companies but its main target has been Ukrainian government agencies and Kiev politicians.