Telecom Malaysia (AS4788) was leaking a full routing table to a Tier 1 network, Global Crossing (AS3549), who in turn was advertising the prefixes to its peers like Level3 (AS3356). Large portions of the Internet would have been affected.

This is a double fail, both for Telecom Malaysia for leaking a full routing table, and for GBLX who apparently isn't filtering prefixes from their downstream customers or even restricting to a max number of prefixes.