Quote:A new phishing campaign uses an innovative technique to compromise targets by sending malicious e-mails to existing e-mail threads to deceive its victims. 

As reported by Trend Micro's Cyber Safety Solutions Team, the spam campaign they discovered during September 2018 uses more complex methods to infect its target and to avoid detection.
Moreover, the phishing campaign will use hijacked e-mail accounts to send a malware payload camouflaged as a part of an ongoing e-mail conversation thread. This allows the bad actors to hide in plain sight and take advantage of their victims' momentary lapse of attention to drop a URSNIF malware payload designed to steal a wide range of data from the compromised machines.