Crooks noticed the high earning potential of rogue online pharmacies from the very start, and the World Health Organization now estimates that more than 50 percent of prescriptions ordered online are counterfeit and either contain the wrong active ingredient or not enough of the active ingredient.
So how can you spot a rogue online pharmacy?
For one thing, a rogue pharmacy will sell you drugs without a doctor's prescription.
Secondly, if you can't find the information about the location of the pharmacy on the website, you should assume that it's probably a rogue one.
"Not knowing the source of a medication should be cause for concern regarding the safety and effectiveness of the prescription," points out Yasmin Vazquez, a specialist with the Association of Certified Fraud Examiners (ACFE).
By the same token, try to find contact information on the website. Legitimate pharmacies will have a licensed pharmacist on staff to answer any question customers may have and instruct them on the drug's side effects, interaction with other pharmaceuticals, etc. If you can't contact a live person that works for the pharmacy, don't buy anything from them.
Also, if you receive drugs without a lot number, expiration date or label, the chances are high that the drugs are counterfeit - and that means that there is no guarantee that they work or even that they are not dangerous. Needless to say, don't use them for your ailments.
And lastly, if you receive spam email advertising drugs that users might be uncomfortable buying in a brick-and-mortar pharmacy (such as erectile dysfunction drugs and other controlled substances), don't accept the offer. Not only will you end up buying questionable pharmaceuticals, but you will be in danger of having your credit card information stolen or getting served with malware.
Of course, there are sites out there that do some of these things right - for example, they employ doctors without a license to approve orders - so users are advised to always be extra careful when buying drugs online.
There are also sites out there that can confirm whether the online pharmacy of your choice is legitimate.
In the US, the National Association of Boards of Pharmacy (www.nabp.net) has created the Verified Pharmacy Practices Sites Program, which lists approved and authorized online pharmacies. In addition to this, they also offer a list of identified fraudulent sites to help avoid being scammed.
LegitScript (www.legitscript.com) also provides a list of 240 safe online pharmacies and more than 42,000 fraudulent ones. UK citizens can search for such lists on the Medicines and Healthcare products Regulatory Agency's website (www.mhra.gov.uk).
By subscribing to our early morning news update, you will receive a daily digest of the latest security news published on Help Net Security.
With over 500 issues so far, reading our newsletter every Monday morning will keep you up-to-date with security risks out there.