Experts who wrestled with SolarWinds hackers say cleanup could take months - or longer

FILE PHOTO: A SolarWinds sign is seen outside its headquarters in Austin, Texas, U.S., December 18, 2020. REUTERS/Sergio Flores/File Photo

WASHINGTON (Reuters) - Cybersecurity expert Steven Adair and his team were in the final stages of purging the hackers from a think tank's network earlier this year when a suspicious pattern in the log data caught their eye.

The spies had not only managed to break back in – a common enough occurrence in the world of cyber incident response – but they had sailed straight through to the client's email system, waltzing past the recently refreshed password protections like they didn't exist.