Reproduction steps:
1. Open the project "IndexFormatCorruption.zip";
2. Select Tools -> Asset Bundles -> Build All;
3. Select Tools -> Asset Bundles -> Hash All
4. Go to the folder "AssetBundles" at the root of the project and check the bundles the hash in their names;
5. Repeat the steps 2 and 3;
6. Compare the new hash values with the ones from the step 4.

Expected results: the values will be the same.
Actual results: the values are completely different after building bundles again.

Reproduced on: 2017.3.2f1, 2017.4.0f1, 2017.4.6f1, 2018.1.7f1.
Not reproduced on: 2017.3.1p4, 2018.2.0b1, 2018.2.0b11, 2018.3.0a3.