News reports say that there has been another cluster of undersea cable cuts affecting the Middle East and south Asia. A cluster early this year gave rise to many conspiracy theories, though that incident was ultimately linked to a ship dragging its anchor.
Naturally, the conspiracy theories are afoot again. If you want to participate, note that
The answer seems more benign. The BBC story notes that "some seismic activity was reported near Malta shortly before the cut was detected". A quick web search shows a 5.3 magnitude quake near Sicily. (A search shows only one other quake near there, in Greece on December 13.) From the timing, the Sicilian quake didn't cut the cables directly; it could, however, have left conditions ripe for an underwater landslide.