Microsoft confirmed that hackers behind a widespread attack on SolarWinds—used by federal government agencies—also breached its systems. The hackers were able to access internal Microsoft systems and viewed source code used to create software products, the Redmond, Washington-based firm said on Thursday. “We detected unusual activity with a small number of internal accounts and upon review, we discovered one account had been used to view source code in a number of source code repositories,” the company wrote in a post on its website. “The account did not have permissions to modify any code or engineering systems and our investigation further confirmed no changes were made. These accounts were investigated and remediated.” According to Microsoft, the hackers were not able to access customer data or Microsoft production services. Microsoft didn’t say what internal systems or products were affected by the breach. “The investigation, which is ongoing, has also found no indications that …