Hackers have compromised the website of the city of Johannesburg, South Africa, and demanded ransom in Bitcoins (BTC).

The city announced the hack on its official Twitter account on Oct. 25. The city wrote that it had “detected a network breach which resulted in unauthorised access to its information systems.” As a result, the breach affected several customer-facing systems — hardware or software customers interact with directly, such as user interfaces and help desks. The breach has frozen those operations.

The ransom and investigation

Following the attack, cybercriminals calling themselves Shadow Kill Hackers demanded ransom worth 4 BTC, as local news outlet eNCA reported earlier in the day. Otherwise, the hackers threatened to upload all compromised data on the Internet by Oct. 28:

"If you pay on time, we will destroy all the data we have, and we will send your IT a full report about how we hacked your systems and your security holes."

The City of Johannesburg cybersecurity experts launched an investigation into the incident which is expected to take 24 hours.

Crypto-related disturbances in the country

As reported by Cointelegraph in July, an angry mob in Ladysmith, South Africa reportedly torched the residence of Sphelele Mbatha, known as Sgumza, a manager of alleged crypto Ponzi scheme Bitcoin Wallet. The mob was likely a collection of victims who lost money through Bitcoin Wallet.

That same month, South Africa was trading Bitcoin at almost $11,000 on the crypto exchange Luno, which was 10.5% higher than Cointelegraph’s price index at the time. Adamant Capital partner Tuur Demeester, however, cautioned that the listed price likely represents “inflation that is simply not recognized by the government.”