DDoS Trojan attacks

Have you encountered with DDoS Trojan attack?

It’s a familiar issue to all SysAdmins, when we work on DDoS attack. Normally, the top command shows a suspicious process with a random name like, Xdrgwdjd, jjiiyaykzg etc or some system commands like ls, ifconfig, pwd, ping, awk, telnet etc.

When we kill that task another random process is being generated immediately.

Steps to fixing the attack :
———————

1) List the files under hourly cron. If you can see any .sh file, please open it.

root@vps-# ls -la /etc/cron.hourly/

++++++++++
# ls /etc/cron.hourly/
freshclam gcc.sh
++++++++++

2) If the .sh file is showing similar data as shown below, then it’s a Virus program!!

root@vps-# cat /etc/cron.hourly/gcc.sh

++++++++++
cat /etc/cron.hourly/gcc.sh
#! / Bin / sh
PATH = / bin: / sbin: / usr / bin: / usr / sbin: / usr / local / bin: / usr / local / sbin: / usr / X11R6 / bin
for i in `cat / proc / net / dev | grep: | awk -F: {‘print $ 1’}`; do ifconfig $ i up & done
cp /lib/libudev.so /lib/libudev.so.6
/lib/libudev.so.6
++++++++++

3) Now, please don’t be hurry! Stay calm and easy

# Do not delete gcc.sh or do not remove the crontab. If you do delete or remove it, then another process will generate immediately.

# You can either remove the culprit script or disable it. [ I prefer to disable it to show the proof to the customer ]

root@vps-# rm -f /etc/cron.hourly/gcc.sh;

OR

root@vps- # chmod 0 /etc/cron.hourly/gcc.sh; chattr +ia /etc/cron.hourly/gcc.sh; chattr + i /etc/crontab

4) Use top command to view virus or malicious file ( Eg :”mtyxkeaofa” ) PID is 16621, do not directly kill the program, otherwise it will again produce, but to stop its operation use the below command.

———————————-
root@vps- # kill -STOP 16621

# Delete files within /etc/init.d. or disable it [ I prefer to disable it to show the proof to the customer ]

root@vps-# find /etc -name '* mtyxkeaofa *' | xargs rm -f

OR

chmod 0 /usr/bin/mtyxkeaofa;
chmod 0 /etc/init.d/mtyxkeaofa;
chattr +ia /usr/bin/mtyxkeaofa;
chattr +ia /etc/init.d/mtyxkeaofa;

———————————-

6) Delete /usr/bin inside archives.

root@vps-# rm -f /usr/bin/mtyxkeaofa;

7) Check /usr/bin archives recent changes, the virus can also be deleted if the other suspect is the same directory.

root@vps-# ls -lt /usr/bin | head

8) Now kill the malicious program, it will not produce.

root@vps-# pkill mtyxkeaofa

9) Remove the virus body.

root@vps-# rm -f /lib/libudev.so

This trojan is also know as Chinese Chicken Multiplatform DoS botnets Trojan, Unix – Trojan.DDoS_XOR-1, Embedded rootkit,

Note :

~ If you are unable to find .sh file, you may please install ClamAV, RKHunter and check logs/report to find the suspicious/malicious

Isaac Adams-Hands

Full Stack Developer, Digital Marketer, and InfoSec enthusiast. He received his Bachelor’s Degree from the University of Western Sydney and his Business Diploma from Georgian College before joining various marketing positions in search portals, e-commerce, higher education, and addiction recovery services.

Follow @ twitter

Related posts

[How-to] Host a static website with Google Cloud – GCP

This step-by-step guide shows you how to set up a Cloud Storage bucket to host a static website. Static websites can include client-side codings such as HTML, CSS, and JavaScript. They cannot contain dynamic code such as server-side scripts such as PHP. Why Google Cloud Storage? It is amazingly fast for pennies a month! You… Read More

Staying off mailing lists

Just saw an article I would like to read, but I noticed it was set up that you had to give all of your information to the business. Normally, I don’t mind, but this time I found how much I had to give away (personal information) wasn’t worth the skimming I’d most likely do when… Read More