Posts Tagged ‘spammer’

Finding spam sending php scripts on multiple sites servers – Tracing and stopping spammer PHP scripts

Monday, April 14th, 2014

stop_php_mail-spam-find-spammer-and-stop-php-spammer-websites
Spam has become a severe issue for administrators, not only for mail server admins but also for webshosting adms. Even the most secure spam protected mail server can get affected by spam due to fact it is configured to relay mail from other servers acting as web hosting sites.

Webhosting companies almost always suffer seriously from spam issues and often their mail servers gets blocked (enter spam blacklists), because of their irresponsible clients uploading lets say old vulnerable Joomla, WordPress without Akismet or proper spam handling plugin,a CMS which is not frequently supported / updated or custom client insecure php code.

What I mean is Shared server A is often configured to sent mail via (mail) server B. And often some of the many websites / scripts hosted on server A gets hacked and a spam form is uploaded and tons of spam start being shipped via mail server B.

Of course on mail server level it is possible to configure delay between mail sent and adopt a couple of policies to reduce spam, but the spam protection issue can't be completely solved thus admin of such server is forced to periodically keep an eye on what mail is sent from hosting server to mail server.
 


If you happen to be one of those Linux (Unix) webhosting admins who find few thousand of spammer emails into mail server logs or your eMail server queue and you can't seem to find what is causing it, cause there are multiple websites shared hosting using mainly PHP + SQL and you can't identify what php script is spamming by reviewing  Apache log / PHP files. What you can do is get use of:

PHP mail.log directive

Precious tool in tracking spam issues is a PHP Mail.log parameter, mail log paramater is available since PHP version >= 5.3.0 and above.
PHP Mail.log parameter records all calls to the PHP mail() function including exact PHP headers, line numbers and path to script initiating mail sent.

Here is how it is used:
 

1. Create empty PHP Mail.log file

touch /var/log/phpmail.log

File has to be writtable to same user with which Apache is running in case of Apache with SuPHP running file has to be writtable by all users.

On Debian, Ubunut Linux:

chown www:data:www-data /var/log/phpmail.log

On CentOS, RHEL, SuSE phpmail.log has to be owned by httpd:

chown httpd:httpd /var/log/phpmail.log

On some other distros it might be chown nobody:nobody etc. depending on the user with which Apache server is running.

 

2. Add to php.ini configuration following lines

mail.add_x_header = On
mail.log = /var/log/phpmail.log

PHP directive instructs PHP to log complete outbund Mail header sent by mail() function, containing the UID of the web server or PHP process and the name of the script that sent the email;
 

(X-PHP-Originating-Script: 33:mailer.php)


i.e. it will make php start logging to phpmail.log stuff like:
 

 

mail() on [/var/www/pomoriemonasteryorg/components/com_xmap/2ktdz2.php:1]: To: info@globalremarketing.com.au — Headers: From: "Priority Mail" <status_93@pomoriemon
astery.org> X-Mailer: MailMagic2.0 Reply-To: "Priority Mail" <status_93@pomoriemonastery.org> Mime-Version: 1.0 Content-Type: multipart/alternative;boundary="——
—-13972215105347E886BADB5"
mail() on [/var/www/pomoriemonasteryorg/components/com_xmap/2ktdz2.php:1]: To: demil7167@yahoo.com — Headers: From: "One Day Shipping" <status_44@pomoriemonastery.
org> X-Mailer: CSMTPConnectionv1.3 Reply-To: "One Day Shipping" <status_44@pomoriemonastery.org> Mime-Version: 1.0 Content-Type: multipart/alternative;boundary="—
——-13972215105347E886BD344"
mail() on [/var/www/pomoriemonasteryorg/components/com_xmap/2ktdz2.php:1]: To: domainmanager@nadenranshepovser.biz — Headers: From: "Logistics Services" <customer.
id86@pomoriemonastery.org> X-Mailer: TheBat!(v3.99.27)UNREG Reply-To: "Logistics Services" <customer.id86@pomoriemonastery.org> Mime-Version: 1.0 Content-Type: mult
ipart/alternative;boundary="———-13972215105347E886BF43E"
mail() on [/var/www/pomoriemonasteryorg/components/com_xmap/2ktdz2.php:1]: To: bluesapphire89@yahoo.com — Headers: From: "Priority Mail" <status_73@pomoriemonaster
y.org> X-Mailer: FastMailer/Webmail(versionSM/1.2.6) Reply-To: "Priority Mail" <status_73@pomoriemonastery.org> Mime-Version: 1.0 Content-Type: multipart/alternativ
e;boundary="———-13972215105347E886C13F2"

 

On Debian / Ubuntu Linux to enable this logging, exec:

echo 'mail.add_x_header = On' >> /etc/php5/apache2/php.ini
echo 'mail.log = /var/log/phpmail.log' >> /etc/php5/apache2/php.ini


I find it useful to symlink /etc/php5/apache2/php.ini to /etc/php.ini its much easier to remember php location plus it is a standard location for many RPM based distros.

ln -sf /etc/php5/apache2/php.ini /etc/php.ini

Or another "Debian recommended way" to enable mail.add_x_header logging on Debian is via:

echo 'mail.add_x_header = On' >> /etc/php5/conf.d/mail.ini
echo 'mail.log = /var/log/phpmail.log' >> /etc/php5/conf.d/mail.ini

On Redhats (RHEL, CentOS, SuSE) Linux issue:

echo 'mail.add_x_header = On' >> /etc/php.ini
echo 'mail.log = /var/log/phpmail.log' >> /etc/php.ini

3. Restart Apache

On Debian / Ubuntu based linuces:

/etc/init.d/apache2 restart

P.S. Normally to restart Apache without interrupting client connections graceful option can be used, i.e. instead of restarting do:

/etc/init.d/apache2 graceful

On RPM baed CentOS, Fedora etc.:

/sbin/service httpd restart

or

apachectl graceful
 

4. Reading the log

To review in real time exact PHP scripts sending tons of spam tail it:

tail -f /var/log/phpmail.log

 

mail() on [/var/www/remote-admin/wp-includes/class-phpmailer.php:489]: To: theosfp813@hotmail.com — Headers: Date: Mon, 14 Apr 2014 03:27:23 +0000 Return-Path: wordpress@remotesystemadministration.com From: WordPress Message-ID: X-Priority: 3 X-Mailer: PHPMailer (phpmailer.sourceforge.net) [version 2.0.4] MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="UTF-8"
mail() on [/var/www/pomoriemonasteryorg/media/rsinstall_4de38d919da01/admin/js/tiny_mce/plugins/inlinepopups/skins/.3a1a1c.php:1]: To: 2070ccrabb@kiakom.net — Headers: From: "Manager Elijah Castillo" <elijah_castillo32@pomoriemonastery.org> X-Mailer: Mozilla/5.0 (Windows; U; Windows NT 5.0; es-ES; rv:1.9.1.7) Gecko/20100111 Thunderbird/3.0.1 Reply-To: "Manager Elijah Castillo" <elijah_castillo32@pomoriemonastery.org> Mime-Version: 1.0 Content-Type: multipart/alternative;boundary="———-1397463670534B9A76017CC"
mail() on [/var/www/pomoriemonasteryorg/media/rsinstall_4de38d919da01/admin/js/tiny_mce/plugins/inlinepopups/skins/.3a1a1c.php:1]: To: 20wmwebinfo@schools.bedfordshire.gov.uk — Headers: From: "Manager Justin Murphy" <justin_murphy16@pomoriemonastery.org> X-Mailer: Opera Mail/10.62 (Win32) Reply-To: "Manager Justin Murphy" <justin_murphy16@pomoriemonastery.org> Mime-Version: 1.0 Content-Type: multipart/alternative;boundary="———-1397463670534B9A7603ED6"
mail() on [/var/www/pomoriemonasteryorg/media/rsinstall_4de38d919da01/admin/js/tiny_mce/plugins/inlinepopups/skins/.3a1a1c.php:1]: To: tynyrilak@yahoo.com — Headers: From: "Manager Elijah Castillo" <elijah_castillo83@pomoriemonastery.org> X-Mailer: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; pl; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 Reply-To: "Manager Elijah Castillo" <elijah_castillo83@pomoriemonastery.org> Mime-Version: 1.0 Content-Type: multipart/alternative;boundary="———-1397463670534B9A7606308"
mail() on [/var/www/pomoriemonasteryorg/media/rsinstall_4de38d919da01/admin/js/tiny_mce/plugins/inlinepopups/skins/.3a1a1c.php:1]: To: 2112macdo1@armymail.mod.uk — Headers: From: "Manager Justin Murphy" <justin_murphy41@pomoriemonastery.org> X-Mailer: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; pl; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 Reply-To: "Manager Justin Murphy" <justin_murphy41@pomoriemonastery.org> Mime-Version: 1.0 Content-Type: multipart/alternative;boundary="———-1397463670534B9A76086D1"

 

As you can see there is a junky spam mails sent via some spammer script uploaded under name .3a1a1c.php, so to stop the dirty bastard, deleted the script:

rm -f /var/www/pomoriemonasteryorg/media/rsinstall_4de38d919da01/admin/js/tiny_mce/plugins/inlinepopups/skins/.3a1a1c.php

It is generally useful to also check (search) for all hidden .php files inside directoring storing multiple virtualhost websites, as often a weirdly named hidden .php is sure indicator of either a PHP Shell script kiddie tool or a spammer form.

Here is how to Find all Hidden Perl / PHP scripts inside /var/www:

find . -iname '.*.php'
./blog/wp-content/plugins/fckeditor-for-wordpress-plugin/ckeditor/plugins/selection/.0b1910.php
./blog/wp-content/plugins/fckeditor-for-wordpress-plugin/filemanager/browser/default/.497a0c.php
./blog/wp-content/plugins/__MACOSX/feedburner_feedsmith_plugin_2.3/._FeedBurner_FeedSmith_Plugin.php

find . -iname '.*.pl*'

….

Reviewing complete list of all hidden files is also often useful to determine shitty cracker stuff

 find . -iname ".*"

Debugging via  /var/log/phpmail.log enablement is useful but is more recommended on development and staging (QA) environments. Having it enable on productive server with high amounts of mail sent via PHP scripts or just on dedicated shared site server could cause both performance issues, hard disk could quickly get and most importantly could be a severe security hole as information from PHP scripts could be potentially exposed to external parties.


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How to disable spammer domain in QMAIL mail server with badmailto variable

Thursday, July 12th, 2012

I've recently noticed one of the qmail SMTP servers I adminster had plenty of logged spammer emails originating from yahoo.com.tw destined to reache some random looking like emails (probably unexisting) again to *@yahoo.com.tw

The spam that is tried by the spammer is probably a bounce spam, since it seems there is no web-form or anything wrong with the qmail server that might be causing the spam troubles.
As a result some of the emails from the well configured qmail (holding SPF checks), having a correct existing MX, PTR record and even having configured Domain Keys (DKIM) started being marked, whether emails are sent to *@yahoo.com legit emails.

To deal with the shits, since we don't have any Taiwanese (tw) clients, I dediced to completely prohibit any emails destined to be sent via the mail server to *@yahoo.com.tw. This is done via /var/qmail/control/badmailto qmail control variable;

Here is content of /var/qmail/control/badmailto after banning outgoing emails to yahoo.com.tw;;;

qmail:~# cat /var/qmail/control/badmailto
[!%#:\*\^]
[\(\)]
[\{\}]
@.*@
*@yahoo.com.tw

The first 4 lines are default rules, which are solving a lot of badmailto common sent emails. Thanks God after a qmail restart:

qmail:~# qmailct restart
....

Checking in /var/log/qmail-sent/current, there are no more outgoing *@yahoo.com.tw destined emails. Problem solved …


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Xtractor Extreme, Power Email Harvester and AMS (Advanced Mass Sender) three Windows programs to Beware of

Monday, August 15th, 2011

AMS (Advanced Mass Sender /Spammer) , POwer Email Harvester, Xtractor Extreme Pro Windows VPS screenshot

Few days ago, I’ve catch some Spammers on some of the servers running Windows inside Virtual Private Servers.

I was doubting if I want to write an article to mention about this 3 piece of software as it might be a bit boury however eventually I thought the goods of it will be better so I just took minutes and wrote it.

Back to the topic the three programs which the spammer was installed and prepare to do his spamming job on the VPS server was:
1. Xtractor Extreme

2. Power Email Harvester

3. Advanced Mass Sender

In order to hide his real IP address and prevent the IP he was spamming, he has also installed some anonyous proxy like Windows software called Hide My IP

The first program Xtractor is basicly an Email collector, the program crawls the net and searches to match email string on web pages.
It get target websites from major search engines.
You put an email like @gmail.com inside it and it starts spidering and grabs all email strings under the domain @gmail.com. Besides that Xtractor Extreme Pro is freeware and can be easily downloaded from many locations online.

Power Email Harvester‘s program name is also quite self-explanatory, what it does is it digs the net for email addresses and generates spam lists … This is the ultimate tool for a spammer, however the guys who create this piece of disruptive software has branded it as “a marketing tool” and even sold and advertised as a tool to help an e-marketing campaign.
This is of course just a word play and in fact in my viewe these program should be prohibited by international law.

Advanced Mass Sender is another piece of Spammer software which officially is tagged as marketing software and is sold and recommended as an useful tool for e-marketing.

I’ve take the time to take a quick and test the spammer installed AMS , honestly I’ve been amazed how far spamming has went during the last 5 years.

This AMS shit is capable of creating a target groups which could easily be spammed whether each group can contain up to 200000+ ! target emails
Advanced Mass Sender can even check if a certain email is present on the remote mail server and only then tries to deliver.
Besides that it even supports sending the spam mails via multiple mail servers (simultaneously) to increase the thoroughput as well as supports proxy servers…

I decided to write this few lines article to raise some awareness about this shitty sofware in a hope that somebody who is Administrating / Supporting client owned Windows servers or Virtual Private Servers will be able to read about this 3 ones and stop spammers before they succeed to create mail havoc with their ugly spam stuff.


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Scanning shared hosting servers to catch abusers, unwanted files, phishers, spammers and script kiddies with clamav

Friday, August 12th, 2011

Clamav scanning shared hosting servers to catch abusers, phishers, spammers, script kiddies etc.  logo

I’m responsible for some GNU/Linux servers which are shared hosting and therefore contain plenty of user accounts.
Every now and then our company servers gets suspended because of a Phishing websites, Spammers script kiddies and all the kind of abusers one can think of.

To mitigate the impact of the server existing unwanted users activities, I decided to use the Clamav Antivirus – open source virus scanner to look up for potentially dangerous files, stored Viruses, Spammer mailer scripts, kernel exploits etc.

The Hosting servers are running latest CentOS 5.5. Linux and fortunately CentOS is equipped with an RPM pre-packaged latest Clamav release which of the time of writting is ver. (0.97.2).

Installing Clamav on CentOS is a piece of cake and it comes to issuing:

[root@centos:/root]# yum -y install clamav
...

After the install is completed, I’ve used freshclam to update clamav virus definitions

[root@centos:/root]# freshclam
ClamAV update process started at Fri Aug 12 13:19:32 2011
main.cvd is up to date (version: 53, sigs: 846214, f-level: 53, builder: sven)
WARNING: getfile: daily-13357.cdiff not found on remote server (IP: 81.91.100.173)
WARNING: getpatch: Can't download daily-13357.cdiff from db.gb.clamav.net
WARNING: getfile: daily-13357.cdiff not found on remote server (IP: 163.1.3.8)
WARNING: getpatch: Can't download daily-13357.cdiff from db.gb.clamav.net
WARNING: getfile: daily-13357.cdiff not found on remote server (IP: 193.1.193.64)
WARNING: getpatch: Can't download daily-13357.cdiff from db.gb.clamav.net
WARNING: Incremental update failed, trying to download daily.cvd
Downloading daily.cvd [100%]
daily.cvd updated (version: 13431, sigs: 173670, f-level: 60, builder: arnaud)
Downloading bytecode.cvd [100%]
bytecode.cvd updated (version: 144, sigs: 41, f-level: 60, builder: edwin)
Database updated (1019925 signatures) from db.gb.clamav.net (IP: 217.135.32.99)

In my case the shared hosting hosted websites and FTP user files are stored in /home directory thus I further used clamscan in the following way to check report and log into file the scan results for our company hosted user content.

[root@centos:/root]# screen clamscan -r -i --heuristic-scan-precedence=yes --phishing-scan-urls=yes --phishing-cloak=yes --phishing-ssl=yes --scan-archive=no /home/ -l /var/log/clamscan.log
home/user1/mail/new/1313103706.H805502P12513.hosting,S=14295: Heuristics.Phishing.Email.SpoofedDomain FOUND/home/user1/mail/new/1313111001.H714629P29084.hosting,S=14260: Heuristics.Phishing.Email.SpoofedDomain FOUND/home/user1/mail/new/1305115464.H192447P14802.hosting,S=22663: Heuristics.Phishing.Email.SpoofedDomain FOUND/home/user1/mail/new/1311076363.H967421P17372.hosting,S=13114: Heuristics.Phishing.Email.SpoofedDomain FOUND/home/user1/mail/domain.com/infos/cur/859.hosting,S=8283:2,S: Heuristics.Phishing.Email.SSL-Spoof FOUND/home/user1/mail/domain.com/infos/cur/131.hosting,S=6935:2,S: Heuristics.Phishing.Email.SSL-Spoof FOUND

I prefer running the clamscan in a screen session, because it’s handier, if for example my ssh connection dies the screen session will preserve the clamscan cmd execution and I can attach later on to see how scan went.

clamscan of course is slower as it does not use Clamav antivirus daemon clamd , however I prefer running it without running the daemon, as having a permanently running clamd on the servers sometimes creates problems or hangs and it’s not really worthy to have it running since I’m intending to do a clamscan no more than once per month to see some potential users which might need to be suspended.

Also later on, after it finishes all possible problems are logged to /var/log/clamscan.log , so I can read the file report any time.

A good idea might also be to implement the above clamscan to be conducted, once per month via a cron job, though I’m still in doubt if it’s better to run it manually once per month to search for the malicious users content or it’s better to run it via cron schedule.

One possible pitfall with automating the above clamscan /home virus check up, might be the increased load it puts to the system. In some cases the Webserver and SQL server might be under a heavy load at the exactly same time the clamscan cron work is running, this might possible create severe issues for users websites, if it’s not monitored.
Thus I would probably go with running above clamscan manually each month and monitor the server performance.
However for people, who have “iron” system hardware and clamscan file scan is less likely to cause any issues, probably a cronjob would be fine. Here is sample cron job to run clamscan:

10 05 01 * * clamscan -r -i --heuristic-scan-precedence=yes --phishing-scan-urls=yes --phishing-cloak=yes --phishing-ssl=yes --scan-archive=no /home/ -l /var/log/clamscan.log >/dev/null 2>&1

I’m interested to hear if somebody already is using a clamscan to run on cron without issues, once I’m sure that running it on cron would not lead to server down-times, i’ll implement it via cron job.

Anyone having experience with running clamscan directory scan through crond? 🙂


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