Windows virus scanners with scrutinized sources

Question

I am growing concerned with the volume of likely state-sponsored malware and related attacks¹.

I am worried that many nations have legislation allowing them to issue orders or otherwise compromise private endeavor² and often suppress discussion of these orders with gag orders.³

I am starting to consider the provenance and integrity of my virus scanner to be important.

I would like a virus scanner that:

1. Has an engine that is routinely scrutinized, and
2. Has virus definition data that is routinely scrutinized.

I would consider these conditions met if:

1. The above components are published Open Source, or
2. Are scrutinized by a trusted digital rights organization like EFF or ORG.

Additional features required:

1. Support for the Windows operating system.

Desirable features:

1. Choice of real-time, on-demand or scheduled scanning
2. Performance characteristics that compare with traditional commercial offerings
3. Detection characteristics that compare with traditional commercial offerings

References:

1: Attacks such as: CIPAV, Flame, Stuxnet, Mask and recently NSA Radio Hacks.

2: Compromises such as: the Clipper Chip, cryptography export restrictions, and recently PRISM.

3: Gags such as : National security letters e.g Twitter Subpoena

Notes:

• Related story about Avast harvesting visited URLs using a browser extension.
• Related story about NSA and GCHQ targeting antivirus software network traffic containing reports of hardware/software present on a system. (slides‌​).

Answer 1

ClamAV is Open Source, and I know that researchers and individuals scrutinize its source code.

I don't think any organization is tasked with auditing it on a regular basis, though.