A company that runs a VPN service for Iranian customers said that attempts by the government to block the service over the weekend have failed.
Iran tried to block VPN ports all over the country to stop citizens seeing banned sites like Facebook and Skype.
But the owner of a Brazilian VPN says that it has been unaffected.
The Stuxnet worm, used to attack nuclear reprocessing plants in Iran, was targeting the country as early as 2005, say reseqarchers at security firm Symantec.
China's Huawei - the world's second largest telecoms firm, but certainly not its most trusted - has been accused of involvement in a plan to sell equipment to Iran.
The Flame virus discovered last week targeting computers in Iran has been ordered to self-destruct, leaving no trace - and no indication of who created it.
The Iranian government says it has a removal tool for the Flame malware targeting the country's oil industry, and says it will give it to any Iranian organization that's been affected.
