The overnight big boy was sentenced to prison on Wednesday.

Amuegbunam pleaded guilty in March to one count of conspiracy to commit wire fraud.

He has been in custody since his arrest in Baltimore in August 2015.

According to the statement released by U.S. attorney’s office in Dallas, the suspect duped at least 10 victims and resulted in losses of about $3.7 million.

Amuegbunam has also been ordered to pay $615,555 in restitution. From November 2013 through August 2015, Amuegbunam and others, sent fraudulent emails to companies in North Texas and elsewhere including Luminant, Wells Fargo and J.P. Morgan Chase.

The emails were designed to look like a forwarded message, supposedly from a top executive at the company, sent to an employee in the firm’s accounting department who had authority to make financial transfers, the news release said.

The investigation began when two businesses reported to the Dallas FBI office that they had received targeted spear phishing emails. Although the emails appeared to be coming from a company executive, the messages were actually coming from a fake email account.

The fraudulent domain name contained one small difference from the company’s true email address, such as transposed letters. Investigation eventually traced the creation of some of the documents to Amuegbunam.

The FBI has been tracking what they now call business email compromise, or BEC schemes, since 2013. According to the FBI’s Internet Crime Complaint Center (IC3), between January 2015 and December 2016, there was a 2,370% increase in identified exposed losses.

Such scams have led to losses totaling more than $5 billion.