According to Bitcoincharts, they've been down for 11 hours:
http://bitcoincharts.com/markets/I was integrating a trading bot with their API at the time, and it took me an hour of trying to fix the software before I reloaded their site. :facepalm:
BTC-e DNS is handled by Cloudflare (
https://www.cloudflare.com/overview), which should outright prevent or at least mitigate any DDoS attack.
From the domain's WHOIS info, you can see that the DNS records were last updated on:
2013.02.14,
2013.02.17 07:53:59 MSK/MSD,
2013.02.17 11:32:45 MSK/MSD
2013.02.17 12:03:42 MSK/MSD
Their public IP address has also changed at least twice in the last 24 hours, which you can see from the DiG command performed earlier:
$ dig a btc-e.com @brad.ns.cloudflare.com
;; ANSWER SECTION:
btc-e.com. 30 IN A 141.101.123.139
btc-e.com. 30 IN A 190.93.240.139
;; WHEN: Sat Feb 16 23:21:19 2013
$ dig a btc-e.com @brad.ns.cloudflare.com
;; ANSWER SECTION:
btc-e.com. 30 IN A 108.162.204.148
btc-e.com. 30 IN A 108.162.203.148
;; WHEN: Sun Feb 17 20:36:06 2013
$ dig a btc-e.com @brad.ns.cloudflare.com
;; ANSWER SECTION:
btc-e.com. 30 IN A 178.248.232.6
;; WHEN: Sun Feb 17 20:59:51 2013
The two most likely causes of their site being down that I can think of are:
1) They've just moved from their previous DNS hosting provider to Cloudflare to provide increased resistance to the type of attacks they've recently been subjected to.
2) They're moving datacentre or performing critical hardware upgrades
My guess is that they'll be online imminently since the first three IP addresses used earlier today all belonged to Cloudflare, but the most recent one (178.248.232.6) is registered to one Alexander Asimov of Denegnyi lane 18, 119002 Moscow....