Get Permission Email security vendor Mimecast, which was targeted by the SolarWinds supply chain hack in January, reports in a Tuesday update that the hackers used the "Sunburst" backdoor as an initial attack vector to steal source code. But Mimecast says it "found no evidence of any modifications to our source code nor do we believe there was any impact on our products." Mimecast reports that the hackers used the backdoor installed in SolarWinds' Orion network monitoring tool to gain partial access to its production environment. The Tuesday update also notes: "The threat actor accessed certain Mimecast-issued certificates and related customer server connection information. The threat actor also accessed a subset of email addresses and other contact information, as well as encrypted and/or hashed and salted credentials."