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.
I just remembered, GBLX was bought by L3 a few years back - I'm guessing someone has a "tighten up route maps for GBLX ASN" ticket open in their backlog at the Level 3 NOC.
The people managing peering for AS 3356 and AS 3549 should be the same group, no? ("That DB we don't share the URL of" seems to imply as much.)
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.