A dissident Cuban blogger who was hailed last year as a hero of press freedom has again been attacked by the island's government for waging a "cyberwar" against the communist regime.

Yoani Sánchez – whose Generacion Y blog has won numerous prizes and attracted an international readership for its blunt reflections on Cuban life – was the subject of a TV programme on Monday.

The latest in a series of programmes called Cuba's Reasons claimed Sánchez was part of a media campaign intent on "demonising" socialism.

It included grainy videos in which the blogger enters European embassies and the US interests section in Havana, and said she has collected $500,000 [£306,000] in international prizes for her work.

"Cyberwar is not a war of bombs and bullets, but of information, communication, algorithms and bytes. It is the new form of invasion that has originated in the developed world," said the narrator.

The Cuba's Reasons series has tried to show that the US is using new technologies to try to subvert the Havana government.

It has coincided with the trial and conviction of US aid contractor Alan Gross, who has been jailed since December 2009 for allegedly trying to bring the internet to government opponents. Earlier this month, Gross was sentenced to 15 years in prison by a panel of judges in a case that has strained US-Cuba relations.

Sánchez herself has shrugged off the latest attack, taking to Twitter to announce: "I am so happy. Finally the alternative blogosphere on official television, although it's to insult us."

She added: "They don't know what they've done! Pandora's Box has been smashed open!"

Sánchez also thanked all those who had texted her. "I can't keep tweeting all the texts of support," she wrote. "There are too many of them and I have only 10 fingers!"

It is not the first time that Sánchez has drawn the ire of the ruling regime. In November 2009, the blogger said she had been beaten up by a group of thugs hired to silence her as she travelled to a peaceful protest.

And three years ago – shortly after Cuba denied her permission to travel to Spain to collect the prestigious Ortega y Gasset journalism award for her blog – Fidel Castro himself appeared to express his disapproval.

In a book about his relationship with Bolivia, Castro alluded to the fact that Sánchez had told an international news agency that she had been barred from travelling to Europe.

"What is grave isn't so much affirmations of this type that are divulged immediately by imperialism's mass media," the former president wrote, but that there are young Cubans who "assume the job of those who undermine, and of the neocolonial press of the ancient Spanish metropolis that awards them".

In an interview with Spanish newspaper El País in April 2008, Sánchez explained why she blogged: "The official discourse in Cuba is stagnant and that's why blogs offer a fresh perspective. They're like drops of water: each one of them, as it hits the wall, can end up doing a lot of damage – knocking it down. It's the young people who control technology and they often feel moved to express their opinions."