overseas banks , power stations , and even Cadbury factories in Australia last week have issued a new ransom demandAttack.Ransom— and it ’ s for much more money than before . The new ransom note was published in two places on the Dark Web and demanded a paymentAttack.Ransomof 100 Bitcoins , or about $ 340,000 , in return for a private security key that could decrypt any file locked by the Petya/Goldeneye malware . The hackers even opened a chat room and offered to decrypt one file for potential buyers as proof that the key would work , though it ’ s not clear whether this was a bluff . The demandAttack.Ransomwas a significant increase on the ransomware ’ s initial requestAttack.Ransomfor just less than $ 400 in Bitcoin when the malware was launched in the Ukraine last Tuesday before rapidly spreading through computer networks worldwide . Bitcoin transactions show its creators were able to access more than $ 13,000 paidAttack.Ransomby victims , however , even though their email address was suspended by its German provider . It ’ s not known whether victims who paid the ransomAttack.Ransomreceived a security key to unlock their files . The dangerous ransomware affected as many as 16,000 computers in 64 countries , according to security firm Clavister , and crippled the operations of several European companies . Some Australian businesses were also affected through their international connections , including Cadbury factories in Tasmania and Victoria , TNT Express courier services , and the offices of law firm DLA Piper . The demandAttack.Ransomor money came amid growing speculation that the ransomware was not designed to make a profit , but was a form of digital terrorism or industrial espionage . ESET senior research fellow Nick FitzGerald said the Petya malware was designed to kill computers first , and ask for moneyAttack.Ransomsecond . “ ( Being ransomware ) was a mechanism to help hide the trail of a gang of cyber terrorists or spies , ” he said . Mr FitzGerald advised victims not to pay any ransomAttack.Ransomas there was very little chance they would be able to unlock their files .