SILK Road, an underground drug marketplace on the "deep web", is being held ransom by hackers.

The website, which can only be accessed through an encrypted network and whose URL changes constantly, is found on part of the internet known as the "deep web" or "dark web", which is not indexed by standard search engines.

Over the last three days the site has been crippled by a series of denial of service (DoS) attacks which involve flooding sites with traffic created by botnets - essentially computers mimicking humans - causing it to crash.

An administrator of the site posted on its forums that the attacks were the work of an individual who had been trying to blackmail the organisation.

The website posted on Saturday that it had received an email from someone, who goes by the handle "Lance G", threatening to crash the site unless it fronted $5000.

Silk Road is now offering $5000 to anyone with any "information that leads to the arrest and conviction of whoever is behind this extortion attempt".

"I think it might be the same hacker that has been doing the same attack on many websites this week and extorting them for money to stop the attack," a Silk Road member told news.com.au. "He has attacked numerous other websites that sell drugs online. He has also attacked bitcoinstore.com."

Silk Road users pay for goods using encrypted digital currency Bitcoins and access the site using the Tor network, making it very difficult for law enforcement to combat the trade.

Debate on the Silk Road forums suggest a competitor had been scamming money to set up a similar website to Silk Road, and referred to a user named Vladimir who had reportedly taken orders and then run off with members’ cash.

It was also suggested that the user may be an informant for the Drug Enforcement Administration in the US.

This isn't the first time this kind of scam has been used.

In November last year, internet users in the US, Eastern Europe and Australia had their computers disabled by hackers and were told all their personal files and data would be destroyed if they didn't pay a ransom fee of up $500.

A spokesman for the Australian Federal Police told news.com.au that more individuals and businesses were being "held to ransom" by cyber criminals as "organised criminal gangs and motivated individuals understand the technology of the internet and take advantage of the anonymity that comes with it".

The AFP said it and other law enforcement agencies "would not stand for it".

"These groups can operate from countries with less developed legal frameworks and are increasingly sophisticated, operating from a high level of technical ability," the spokesman said.

How to stay protected:

- Individuals and businesses can improve their security by ensuring you use strong passwords, that are regularly changed. Ensuring the physical safety of all electronic and merchant devices is tantamount. Never leave a terminal unattended.



- Beware that criminals may approach you posing as a terminal, electrical or phone line technician claiming the need access to your business terminal. If you give them access they may be able to install card reading technology that allows them to steal credit card information.



- If you’re still using paper receipts or manual paper facilities, ensure that all copies are destroyed in a way that makes the details unreadable.



- Merchants are required to comply with Payment Card Industry Data Security guidelines, which is endorsed by all major credit card brands including Visa, Mastercard, American Express, Diners Club and JCB. Check to ensure you comply with the standards here.



Originally published as Silk Road held to ransom by hackers