A fourth malware strain wielded by the SolarWinds attackers has been detailed by Symantec researchers, followed by the disclosure of the attackers’ ingenous lateral movement techniques and the release of an auditing script by FireEye researchers that organizations can use to check their Microsoft 365 tenants for signs of intrusion.

Then, on Tuesday, Malwarebytes CEO Marcin Kleczynski disclosed that the same attackers targeted and breached the company, but not through the compromised SolarWinds Orion platform (which they don’t use).