Governments all around the world use malware and spyware to keep tabs on people, from visitors to residents. But a security researcher's tool can now determine if your computer is infected with spyware.

The Detekt tool was developed by Berlin-based security researcher Claudio Guarnieri and supported by several human-rights groups. Detekt is checks for malware that is often used against journalists, activists and other people frequently targeted by governments.

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Available as a free download, Detekt is primarily a scanner; its primary purpose is to warn users if they're being spied on, not to remove that spyware. If Detekt does detect spyware, the researchers recommend users disconnect that computer from the Internet and stop using it immediately. Then, users should contact an expert via a computer they don't normally use.

Lists of experts who may be able to help, along with their PGP keys for sending encrypted emails, are available from Detekt's website.

Detekt is currently compatible with Windows XP, Vista, 7, 8 and 8.1. It's available in English, German, Italian, Spanish, Arabic and Amharic, the national language of Ethiopia.

According to Amnesty International, one of Detekt's co-sponsors, an early version of the tool was used to investigate surveillance practices in several countries. Detekt discovered that several human-rights lawyers and activists in Bahrain were being spied on with a commercial piece of spyware called FinSpy.

Amnesty International warns that Detekt can't magically detect all spyware; rather, it is designed to recognize some of the most commonly used and encountered commercial spyware. The developers will continue to update Detekt as the spyware it targets evolves and changes.

"The growing trend in indiscriminate mass surveillance on a global scale was laid bare by the Edward Snowden disclosures," writes Amnesty International in its post on Detekt. "Following the lead of the USA and other industrialized countries, governments everywhere now justify the use of such surveillance. This has a chilling effect on the rights to freedom of expression and peaceful assembly in countries across the world."