Hitman scam

The Hitman scam is a type of email extortion scheme. Victims are reportedly being threatened in an attempt to extort money. The victim receives an email from a member of an organization such as the "Ishmael Ghost Islamic Group." The emailer claims to have been sent to assassinate the victim and the victim’s family members. The emailer asserts that the reason for the impending assassination resulted from an alleged offense, by the victim, against a member of the emailer’s gang.

In a bizarre twist however, the emailer reveals that upon obtaining the victim’s information, another member of the gang (purported to know a member of the victim’s extended family) pleaded for the victim’s pardon. The emailer alleges that an agreement was reached with the pleading gang member to allow the victim pardon from assassination, if the victim takes some action such as sending $800 to a receiver in the United Kingdom for the migration of Islamic expatriates from the United States. Victims of this email are typically instructed to send the money via Western Union® or Money Gram® to a receiver in the United Kingdom. The emailer often gives the victim 72 hours to send the money or else pay with his/her life.

Source
Internet Crime Complaint Center, 2009 Internet Crime Report.