ABS System Buzzing
i appear to have discorvered a new problem, Yesterday was my cars first day out in the rain after I bought it 4 months ago and after parking it in the garage last night I noticed a strange buzzing noise, I looked around and at first thought it was maybe a problem with the fuel pump but remembered the fuel pump is way in the back, I eventually found the noise coming from my abs system and specifically the little black box labeled "ABS ASR" I suspect its a pump but I'm new to working on cars and wanted to ask before I started taking things apart. Thanks.
Here is a youtube video I have uploaded showing the problem, at the time I didn't know the abs system was in the storage area next to this one so I didn't record it directly but you cant see anything happen and you can still hear it well here.



