A friend in AS58587 confirmed that this was caused by a configuration error - it seems like related to redistribution, and they already fixed that.
----- Matsuzaki Yoshinobu <m...@iij.ad.jp> - IIJ/AS2497 INOC-DBA: 2497*629 In message <559252e9.6030...@janoszka.pl> Date: Tue, 30 Jun 2015 10:27:21 +0200 Grzegorz Janoszka <grzeg...@janoszka.pl> wrote > > We have just received alert from bgpmon that AS58587 Fiber @ > Home Limited has hijacked most of our (AS43996) prefixes and > Hurricane Electric gladly accepted them. > > Anybody see their prefixes hijacked as well? > > -- > Grzegorz Janoszka