Black hats steal code-signing keys from software whitelisting anti-malware firm. Pretty audacious
It is accomplished using many vrfs on 2 Cisco 1841s. For those less technical, VRFs are essentially private routing tables similar to a VPN. When a packet destined to 22.214.171.124 (AKA obiwan.scrye.net) hits my main gateway, I forward it onto the first VRF on the “ASIDE” router on 126.96.36.199. That router then has a specific route for 188.8.131.52 to 184.108.40.206, which resides on a different VRF on the “BSIDE” router. It then has a similar set up which points it at 220.127.116.11 which lives in another VPN on “ASIDE” router. All packets are returned using a default route pointing at the global routing table. This was by design so the packets TTL expiration did not have to return fully through the VRF Maze. I am a consultant to Epik Networks who let me use the Reverse DNS for an unused /24, and I used PowerDNS to update all of the entries through mysql. This took about 30 minutes to figure out how to do it, and about 90 minutes to implement.
some good approximation/streaming algorithms and tips on Scala implementation
The Space-Saving algorithm to compute top-k in a stream. I’ve been asking a variation of this problem as an interview question for a while now, pretty cool to find such a neat solution. Pity neither myself nor anyone I’ve interviewed has come up with it ;)
ASL-licensed open source library of stream-processing/approximation algorithms: count-min sketch, space-saving top-k, cardinality estimation, LogLog, HyperLogLog, MurmurHash, lookup3 hash, Bloom filters, q-digest, stochastic top-k
‘We introduce Quantile Digest or q-digest, a novel data structure which provides provable guarantees on approximation error and maximum resource consumption. In more concrete terms, if the values returned by the sensors are integers in the range [1;n], then using q-digest we can answer quantile queries using message size m within an error of O(log(n)/m). We also outline how we can use q-digest to answer other queries such as range queries, most frequent items and histograms. Another notable property of q-digest is that in addition to the theoretical worst case bound error, the structure carries with itself an estimate of error for this particular query.’
Allegedly being used to censor political and anti-corruption journalism, and a Russian wikipedia-like site for hosting an article about suicide
Google and AggregateKnowledge’s improvements to the HyperLogLog cardinality estimation algorithm