That's microfiltered milk and it's actually much worse than UHT:
Microfiltration (MF) of cheese milk has been proposed as an alternative to bactofugation for removal of bacterial spores. However, while good separation efficiency can be obtained, this technology has some drawbacks. First of all, for an efficient MF process, the milk would have to be skimmed prior to MF, which means that the cream phase, constituting ∼10% of milk volume, cannot be treated with MF and would require a high heat treatment to ensure inactivation of spores. Secondly, the MF retentate will typically constitute a considerably large volume than the bactofugate, again meaning that a large volume would have to be sterilized. Together, this could mean the involvement of a considerable proportion of sterilized materials being included in the cheese milk when applying MF for spore removal, with negative effects on cheese-making and cheese quality.
https://www.sciencedirect.com/topics/agricultural-and-biolog...
In short, microfiltered milk is taken apart, sterilised or filtered separately, and then put back together again- probably the most processed kind of milk you can find in the market.