The attacker in this case sent two different phishing emails over a two-day period. The two emails were sent to two small groups of employees...
The email was crafted well enough to trick one of the employees to retrieve it from their Junk mail folder, and open the attached excel file....
The spreadsheet contained a zero-day exploit that installs a backdoor through an Adobe Flash vulnerability...
The attacker first harvested access credentials from the compromised users... performed privilege escalation on non-administrative users...
The attacker then used FTP to transfer many password protected RAR files from the RSA file server to an outside staging server...
The files were subsequently pulled by the attacker and removed from the external compromised host to remove any traces of the attack...