More interesting than the rootkit itself is how it found it's way into the box.
Chances are that Squeeze has a non-disclosed 0day, and that's worring me a bit... On Mon, Nov 26, 2012 at 11:04 AM, dxp <[email protected]> wrote: > Looks like a new rootkit according to Kaspersky [1] and some analysis > released by CrowdStrike [2]. > > [1] > https://www.securelist.com/en/blog/208193935/New_64_bit_Linux_Rootkit_Doing_iFrame_Injections > [2] > http://blog.crowdstrike.com/2012/11/http-iframe-injecting-linux-rootkit.html > > PS: Interesting to know if others found this on their servers or is this > an isolated incident !? > > > On Tue, Nov 13, 2012 at 10:19 AM, stack trace <[email protected]>wrote: > >> Hi there, >> >> We've discovered something which looks to us like a rootkit working >> together with proxy software like nginx. Our OS is debian squeeze and nginx >> 1.2.3. >> >> Here is what happened: >> >> We are running a web service and we got notified by some customers of us >> that they are getting redirected to some malicious sites. Somehow a hacker >> managed to inject an iframe into our http responses. >> >> I tried to do a telnet test on our nginx proxy and saw that even the "bad >> request" response which gets served directly from nginx contained the >> malicious iframe code. >> >> server { >> listen 80 default backlog=2048; >> listen 443 default backlog=2048 ssl; >> server_name _; >> access_log off; >> (...) >> location / { >> return 400; >> } >> } >> >> Doing a bad request nginx doesn't go to cache in this case - the "return >> 400" makes nginx reply with a predefined response (a string in memory). >> >> Even this response contained an iframe like this: >> HTTP/1.1 400 Bad Request >> Server: nginx/1.2.3 >> Date: Wed, 07 Nov 2012 00:01:24 GMT >> Content-Type: text/html >> Content-Length: 353 >> Connection: close >> >> <html> >> <head><title>400 Bad Request</title></head> >> <body bgcolor="white"><style><iframe src="http://malware-site/index.php >> "></iframe></div> >> <center><h1>400 Bad Request</h1></center> >> <hr><center>nginx/1.2.3</center> >> >> We've done an strace on the running nginx process and discovered that the >> reply of the process actually didn't contain the malicious iframe. >> >> writev(3, [{"HTTP/1.1 400 Bad Request\r\nServer"..., 151}, >> {"<html>\r\n<head><title>400 Bad Req"..., 120}, >> {"<hr><center>nginx/1.2.4</center>"..., 52}], 3) = 323 >> >> After a bit deeper digging we've found some kernel rootkit I've attached >> to this email and also some hidden processes were running on our proxy >> machine with names like write_startup_c and get_http_inj_fr (which sounds >> like what happened to us). >> >> Is this a known attack / rootkit etc or did we discover something new? >> >> Cheers, >> -stacktrace >> >> _______________________________________________ >> Full-Disclosure - We believe in it. >> Charter: http://lists.grok.org.uk/full-disclosure-charter.html >> Hosted and sponsored by Secunia - http://secunia.com/ >> > > > > -- > dxp > > _______________________________________________ > Full-Disclosure - We believe in it. > Charter: http://lists.grok.org.uk/full-disclosure-charter.html > Hosted and sponsored by Secunia - http://secunia.com/ > -- just because you're paranoid, don't mean they're not after you... gpgp-fp: 3DB13F197F8A0360814885D1F1F1E2EFAD509AFD skype:rc46fi gplus.to/gregor twitter.com/#/2smart4u
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