Khosro Zare, a former bank-system specialist in Iran, claims he hacked the PIN codes to highlight the vulnerability of Iran’s banking system. Central bank officials had earlier downplayed the reports, saying that the threat to the banking system is not serious. At least three Iranian banks (Saderat, Eghtesad Novin, and Saman) have already sent text messages to their clients, warning them to change their debit card PINs. The warning was repeated on state TV channels.
Source: https://thehackernews.com/2012/04/banking-system-vulnerability-3-million.html