  In this paper, we shed new light on the DNS amplification ecosystem, by
studying complementary data sources, bolstered by orthogonal methodologies.
First, we introduce a passive attack detection method for the Internet core,
i.e., at Internet eXchange Points (IXPs). Surprisingly, IXPs and honeypots
observe mostly disjoint sets of attacks: 96% of IXP-inferred attacks were
invisible to a sizable honeypot platform. Second, we assess the effectiveness
of observed DNS attacks by studying IXP traces jointly with diverse data from
independent measurement infrastructures. We find that attackers efficiently
detect new reflectors and purposefully rotate between them. At the same time,
we reveal that attackers are a small step away from bringing about
significantly higher amplification factors (14x). Third, we identify and
fingerprint a major attack entity by studying patterns in attack traces. We
show that this entity dominates the DNS amplification ecosystem by carrying out
59% of the attacks, and provide an in-depth analysis of its behavior over time.
Finally, our results reveal that operators of various .gov names do not adhere
to DNSSEC key rollover best practices, which exacerbates amplification
potential. We can verifiably connect this operational behavior to misuses and
attacker decision-making.
