C99Shell :: How To Detect Or Disable The Functionality Of C99Shell
Jul 13, 2008
Recently my site was defaced, (i own a dedicated server), my server was not touched, but one of the applications I used on the site was exploited to gain access to it.
I have noticed 4 or 5 c99 shells in different locations on my ftp. The site is back online, but it's definitely possible that they have one of these hidden somewhere and that they'll just do it again. I am using cent os 5
How can I easily search for these on my box? Can I disable their functionality? is there setting I can use in htaccess or something to make my website safer? I visited one of the scripts, and it said SAFEMODE OFF, how can I at least enable safemode?
I don't know much of anything about linux, but I am running cpanel and WHM. I have a guy who manages my box but he is hard to get a hold of sometimes, and I'd like to take care of this ASAP!
the biggest security issue i have with my clients is php c99 shell and similar php files, somehow these files uploaded on the website and from here they start attacking the websites. i have seen also that once you upload the c99 php file you are able to see the accounts information ( such as a user name ) on the same server
so is there any way to disable this kind of php file or at least disable some function within the file!
i have been thinking to install and run a antivirus on the server , but i see sometimes they upload the encrypted version of the file , so the antirus can't catch the file as a torjan!
I just installed zen cart on my webhosting and after few days later i saw some file written like core1405.php and when i open to view the file it is actually trojan c99shell.
I have deleted all of the core file. Now how can i prevent it from happen again? Cause it is too much work to clean up the hosting server.
I installed modsecurity from Addone module in Cpanel
When I try to apply phpshell woork good without a mistakes and I can do anything despite of the presence of protection modsecurity and disable_functions in php.ini.
Is there a particular settings add to the httpd.conf to prevent application phpshell or prevent upload it to the site?
guys im tired off fighting those hackers everyday! i have about 20 websites,and everyday i have one of them hacked! i restore a backup then another one hacked!
thats unbelivable!!!
those bastards upload there shell scripts to websites via bugs or whatever from php files!!
is there anyway to stop these commands?
can .htaccess helps? how?
i talked to my webhosting companies for my websites! ....
I found this rule to detect URI's for the c99 shell.
#new kit SecFilterSelective REQUEST_URI "/c99shell.txt" SecFilterSelective REQUEST_URI "/c99.txt?" My problem is that the hackers are being more stealthy and calling the script some random name like .../myphpstuff.php. So the URI no longer helps detect it.
How could I detect "c99shell" in the actual file that apache servers? This assumes that the hacker was successfully in installing it.
I have few scripts, but hackers again upload at some way c99, and hack some SMF forums at server. Server like server they cannot hack, but user account they can. So please tell me what you advice?
Considering a web site could be completely useless without its web forms working as expected, and the uptime reports do not verify them at all, I would like to know if you people, consider it important.
What this does is amongst others is to add "SHOW USER_STATISTICS" statement do MySQL. What this does is keep statistics on which users on your mysql machine is spending the most time processing queries.
It is also mentioned here: [url]
If you believe this functionality could be important to our industry you are more than welcome to vote for this or add comments to the following feature request:
I accidently found that it could be available to de-activate mod_security in a certain directory by using a .htaccess like that...
<IfModule mod_security.c> SecFilterEngine Off SecFilterScanPOST Off </IfModule>
I believe it's something related to the "AllowOverride" directive from apache but im not exactly sure, the available arguments for this directive are "AuthConfig, FileInfo, Indexes, Limit, Options", I've tried hardly to find a way to not to disable the usage of .htaccess files and keep it's functionality but also to prevent it from being able to modify through it the functionality of mod_security.
I'm sure Anyone here could help me in this issue as it's a big pain for any server running apache in a shared vhosting environment.
I have a private vps server works under linux ( centos ), sometimes am getting msg from csf/firewall subject:
lfd on website.com: Suspicious process running under user user account
when i check my cpanel/whm vps ( service status ) its shows that the memory limit 80% - 85% , It's had a good forum works with vb, but am wonder how to check my vps memory, i mean how to detect if there any script, or malware, or anything takes the vps memory out...
Is there any way to check,know what works under my vps, so it's take my memory limit 85%?
I have a few incomplete steps to see if I got some intruder in my Linux system.. But i really would like to have all your suggestions to make a good doc about this matter,
1.- Download and run Rkhunter & Chkrootkit 2.- Run "w", and "netstat -nalp |grep "SHPORTHERE" to see whos connected using SSH 3.- Search for ssh and ftp accepted logins.
Code: last cat /var/log/secure* | grep ssh | grep Accept cat /var/log/secure* |grep ftp |grep Accept less /var/log/messages | grep ftp 4.- Watch current connections and scan your ports.
Code: netstat -nalp nmap 1-65535 localhost 5.- Search for suspicious content on common explotable dirs.
Code: rm -rf /tmp/sess* rm -rf /var/dos-* rm -rf /var/tmp/ssh-* rm -rf /var/tmp/dos-* ls /tmp -lab ls /var/tmp -labR ls /dev/shm -labR ls /usr/local/apache/proxy -labR ls /usr/local/samba -labR 6.- Checking for anomalies on this files.
Code: less /etc/passwd less /etc/shadow less /etc/groups 7.- Search for new users at sudoers, check wtmp and telnet is not running.
Code: cat /etc/sudoers who /var/log/wtmp cat /etc/xinetd.d/telnet 8.- Find bash history files
is there any proved method to determine what kind of attack you are under? Our server has been under attack for more than a day now but so far we have not been able to find out what kind of attack it is exactly. The server maintence company we are using says it's a DDoS attack but they don't say how they found this out. Also, they are not telling us what kind of DDoS attack it is.
Is there any way to distinguish a dedicated server from VPS using Linux commands and detect the implemented virtualization technology like XEN and OpenVZ, ...?
I have received a dedicated server and in cPanel its written Virtuozzo but they tell me it's XEN , beside this what's the reason to implement a virtualization technic while they give me a dedicated server? Maybe to obtain cheaper cPanel license,
Do web hosts have the means to self-detect or self-correct problems with people's websites? If so, is there a name for this ability?
Seems that every host I've used has to be *told* about major problems, such as the server or database being down completely. I'm tired of going out of town fearing a site crash. I don't expect them to catch every problem, but when the failure is so blatant, it would be nice if they caught it...
If i put domain.com on uptime checker,and downtime is detected,downtime will be reported if dns is down or if http server is down.So question is what i need to do to see what exactly went down?For network uptime i can ping ip adress,but for these two i really don't know.
I know the ISP is RADIGRAFICA COSTARRICENSE, and the server location is San José in Costa Rica.
I googled the ISP name RADIGRAFICA COSTARRICENSE, trying to find out the company site which offer's web hosting service, but I can only find racsa.co.cr; however, this doesn't look like a web hosting company.
On one server which i have sometime appear very high load up to 70,and that causing downtime of few minutes(i have historic data webmin module where i saw high load and downtime time matches,but it doesn't show what causing it).That server also have hardware raid in mirror mode.(copies exact data from one disk to another).
Sometime ago the DC told me there was too many files on server and I started to investigate what is was and i got info that some one hacked the server and was sending spam from it.
When I looked at the accounts in Direct Admin some of them had the contact email to some hacker so i deleted the emails and changed password on the DA account and the email of those accounts.
Still I got too many files all the time so the server goes down so i have to delete the spoolfile all the time like 10 times a day
Please help how do I detect from what account do the hacker operate?
Can I detect that somehow?
Is it possible to do some small script to detect this?
Is there any advanced module to DA that gives me the info?
