Trend Micro has released a multi-ransomware decryptor a while ago, aptly named Trend Micro Ransomware File Decryptor.
It doesn't seem to be very popular on this forum, but other ransomware-related sites and forums often link to it, including NoMoreRansom.
This tool only supports decrypting TeslaCrypt 3.x and 4.x; Trend Micro's site states that a separate "TeslacryptDecryptor 1.0.xxxx MUI" tool is available for earlier versions. Trend Micro strangely refuses to link to this tool, and instead it's only offered on request by their technical support staff. Nevertheless, the download link is quite easy to find with some Google-fu.
I have downloaded this mysterious "TeslacryptDecryptor" to test on some of my TeslaCrypted samples (the ones I originally wrote TeslaCrack for), and I was in for a surprise.
The tool comes as a self-extracting archive, and inside is a wrapper exe, and some precompiled Python files (*.pyc). Opening unfactor.pyc revealed some familiar strings. In fact, it's a compiled version of unfactor-ecdsa.py from TeslaCrack! Likewise, another pyc file turned out to be teslacrack.py in disguise.
Trend Micro included an extensive list of 3rd-party software copyright notices and open-source licenses applying to various code used in the tool, but no acknowledgement is made of TeslaCrack, and no mention of GPLv3. Moreso, the pyc files in question are claimed as "proprietary and confidential information of Trend Micro Incorporated" in the tool's clickwrap license.
Some GPLv2'd components are properly acknowledged, but no sources are published.
Needless to say, this is not the kind of behavior I would have expected from a major player in the PC security market like Trend Micro.