KABUL, Afghanistan  In little more than a year, the Persian-language satellite television channel beamed into Iran by Rupert Murdoch’s News Corporation and a prominent Afghan family has rapidly become one of the most popular stations in the country.

A little too popular, it appears.

This week, a long-running campaign led by the Iranian government to undermine the channel, Farsi1, took a menacing turn: A group calling itself the Iranian Cyber Army hacked into Farsi1’s Web site, as well as several sites owned by the Mohseni family, and posted a cryptic but sinister warning.

“The allies of Zionism should know this,” said the message, which stayed on the Web sites for about six hours on Thursday. “Dreams of destroying the foundation of the family will lead straight to the graveyard.”

The exact meaning of the message was unclear, but conservative Iranian leaders complain that the programming  a heavily censored variety of comedies, soap operas and dramas  is eroding traditional Iranian values.