Germany's domestic secret service says it has evidence that Russia was behind a series of cyber attacks, including one that targeted the German Parliament last year.

The Federal Office for the Protection of the Constitution (BfV) said a hacker group known as "Sofacy" was behind the attack, which forced the German Parliament's computer systems to be shut down for days.

"One of the most active and aggressive campaigns is the 'Sofacy/APT 28' campaign," said the BfV.

The BfV added that it "sees evidence of Russian state control" in the operation that infected computers with Trojan software.

While Sofacy aimed at stealing data, another campaign named "Sandworm" was also designed to sabotage IT systems, the BfV said in a statement.

"Besides targeting government posts, it was also aimed at telecommunications companies, energy providers, as well as higher education facilities," the agency said.

'Readiness' to carry out sabotage

IT experts have said a power failure in parts of Ukraine late last year was down to a "Sandworm" hack.

"The campaigns being monitored by the BfV are generally about obtaining information — that is spying," the agency's chief Hans-Georg Maassen said in a statement.

"However, Russian secret services have also shown a readiness to carry out sabotage."

The Sofacy attack that last year hit the German lower house of Parliament also affected a computer in Chancellor Angela Merkel's legislative office, local media reported.

AFP/Reuters