The hacking group behind the SolarWinds compromise was able to break into Microsoft Corp and access some of its source code, Microsoft said, something experts said sent a worrying signal about the spies’ ambition.

It is not clear how much or what parts of Microsoft’s source code repositories the hackers were able to access, but the disclosure suggests that the hackers who used software company SolarWinds as a springboard to break into sensitive U.S. government networks also had an interest in discovering the inner workings of Microsoft products as well.

Microsoft had already disclosed that like other firms it found malicious versions of SolarWinds’ software inside its network, but the source code disclosure - made in a blog post - is new. After Reuters reported it was breached two weeks ago, Microsoft said it had not “found any evidence of access to production services.”

A Microsoft spokesman said security employees had been working “around the clock” and that “when there is actionable information to share, they have published and shared it.”

The SolarWinds hack is among the most ambitious cyber operations ever disclosed, compromising at least half-a-dozen federal agencies and potentially thousands of companies and other institutions. U.S. and private sector investigators have spent the holidays combing through logs to try to understand whether their data has been stolen or modified.

Modifying source code - which Microsoft said the hackers did not do - could have potentially disastrous consequences given the ubiquity of Microsoft products, which include the Office productivity suite and the Windows operating system. But experts said that even just being able to review the code could offer hackers insight that might help them subvert Microsoft products or services.

Microsoft noted that it allows broad internal access to its code, and former employees agreed that it is more open than other companies.

In its blog post, Microsoft said it had found no evidence of access “to production serv ices or customer data.”

“The investigation, which is ongoing, has also found no indications that our systems were used to attack others,” it said.

Source- Reuters

Country- U.S