The popular home DNA testing kit company 23andMe has revealed it was targeted in a cyberattack that resulted in unauthorized access to individuals' accounts.

23andMe is investigating the breach, which appears localized to users who are part of the company's relative-matching service, DNA Relative. The company encourages all users to reset their passwords and sign up for two-factor authentication.

CyberScoop and other cybersecurity blogs say they have seen data supposedly taken from 23andMe advertised for sale on an online forum. It is unclear how many people were affected by the breach.

The company said the breach may have come as a result of customers using the same username and password for their 23andMe accounts as other online accounts that were less secure and the attacker then using these to get into people's accounts and scrape the data from there of everyone they were matched to as part of the DNA Relative service.

This data can include a person's name, age, sex and location, as well as photographs and genetic ancestry information, including information that may be relevant to a person's health