Not quite. Their "malicious" extension only got a few hundred installs. Using the data gathered by that extension and via other means they were able to locate other actually malicious extensions. Those total in the millions of installations.

Through this process, they have found the following:

1,283 with known malicious code (229 million installs).
8,161 communicating with hardcoded IP addresses.
1,452 running unknown executables.
2,304 that are using another publisher's Github repo, indicating they are a copycat.