The US city of Baltimore's government has effectively been held hostage over the last few weeks because of a ransomware attack that crippled its systems.

Hackers got into the city's servers on 7 May and demanded $100,000 (£79,000) worth of Bitcoin. To date the city has refused to pay.

Citizens are unable to access online sites to pay their water bills, property taxes and parking tickets and about 10,000 city government computers are locked down by the ransomware, leaving employees with no email.

Apparently more than 1,500 homes sales have been delayed because the hackers left the city unable to notify insurers whether the sellers had any outstanding property debts.

The hackers initially set a four day deadline for payment and after 10 days they said the city would not be able to get its data back.
  • The ransomware, called RobbinHood, makes it impossible to access the Baltimore city servers without a specific digital key. 
  • It uses a publicly available algorithm called RSA to encrypt the data and it’s believed that at the very least Baltimore isn’t capable of cracking the encryption. 
  • In a sense, without this key Baltimore has more or less lost everything held on its servers. 
The city is attempting to create manual workarounds until it can restore its server, but it has also acknowledged it is unclear when the systems will be back in operation, which could be months.