A British aircraft broker (Balli Aviation Ltd.) was recently fined $17 million dollars, and put on probation for five years, for illegally exporting three Boeing 747s to Iran two years ago. The broker pled guilty and cooperated with the investigation. Iran has eight Boeing 747s, and they cannot be exported to Iran without a U.S. government permit. The U.S. refuses to provide these permits, so Iran obtains these aircraft via fraud and companies that are willing to risk prosecution. The Boeing and AirBus aircraft obtained this way have to be maintained by Iran, using smuggled parts. As a result, some of these airliners are sidelined for years at a time for lack of spare parts.
Another recent smuggling development was the German arrest of five men for trying to buy nuclear power plant components for a Russian firm that needed them to build an Iranian power plant. Russia was very upset about this, because, as they interpreted the sanctions, this purchase was legal. The Germans disagreed. Russia also refuses to abide by sanctions against selling Iran commercial aircraft. So Iran buys a lot of Russian airliners, even though they would prefer Boeing or AirBus products.
Ever since the U.S. embargo was imposed in 1979 (after Iran broke diplomatic protocol by seizing the American embassy), Iran has sought, with some success, to offer big money to smugglers who can beat the embargo and get needed industrial and military equipment. This is a risky business, and American and European prisons are full of Iranians, and other nationals, who tried, and often failed, to procure forbidden goods. The smuggling operations are currently under more scrutiny, and attack, because of Iran's growing nuclear weapons program. But the Iranians simply offer more money, and more smugglers step up to keep the goodies coming.