Databases, Systems & Networks

Développé par la même personne derrière le scanner de malware Rkhunter, Lynis est un outil qui va vous permettre de réaliser un audit simple de votre machine sous GNU/Linux.

Pour installer Lynis (sous Ubuntu) :

sudo apt-get install lynis

Pour lancer le scan :

sudo lynis -c

Ensuite, l’analyse se fera sur les utilitaires systèmes, le bootloader et les services, le kernel, la mémoire et les processus, tout ce qui est utilisateurs, groupes et authentification, les shells, le système de fichiers, le stockage, NFS, DNS, les ports et les packages, la config réseau, les imprimantes, les logiciels de messagerie, le firewall, le serveur web, la config SSH, SNMP, les bases de données, LDAP, PHP, Squid, les logs, les services non sécurisés, la crontab, les comptes, l’heure et la synchronisation temporelle, le chiffrement, la virtualisation, les frameworks de sécurité présents, les softs de vérification d’intégrité des fichiers, les scanners de malware, les utilitaires systèmes, les répertoires home…etc.

Le scan se termine ensuite par une liste de suggestions plus ou moins longue de petites choses à améliorer pour rendre votre système plus sécurisé.

Pour info, le rapport complet, une fois achevé se trouve ici : /var/log/lynis.log

Par exemple, pour visualiser uniquement les choses qui urgent (Warning), il suffit de faire un petit grep :

sudo grep Warning /var/log/lynis.log

Et pour consulter uniquement les bons conseils de Lynis :

sudo grep Suggestion /var/log/lynis.log

De quoi, déjà, faire un bon petit tour d’horizon sur les faiblesses de votre système et ne rien laisser grand ouvert qu’un méchant hacker pourrait exploiter.

Source: korben.info

Source: Malware Must Die!

The background

.IptabLex & .IptabLes ELF DDoS malware is the malware made by China DDoSer crime group, designed to infect multiple architecture of Linux distribution, was aiming for Linux boxes in the internet with the low security and authentication flaw in SSH as vector of infection, was an emerged ELF threat in 2014.

Historically, MalwareMustDie, NPO (MMD) is the first entity who detected this malware around May last year and named it as Linux .Iptablesx|s on our last year’s alert MMD-0025-2014 [link] released on June 15, 2014. And we build malware repository for this ELF family for sharing samples and trend for researchers and industries on kernelmode started from September 4th 2014 [link], since the threat was gone so wild at the time and there was so few information about this malware that causing low awareness and detection ratio, so we managed all we can to suppress the growth of infection rate.

The DDoS attacks originated from this malware, in quantity of incidents and traffic used, was so massive in 2014 causing some warning was released from important security entities in September 2014, as per announced by Prolexic (thank you for mentioning MalwareMustDie) [link] in their Threat Advisory with « High Risk » level, following by Akamai‘s warning referred to the Prolexic’s advisory announcing the world wide warning [link] of .IptableS|X.

Afterward, Linux .IptableS / .IptablesX ELF malware was still be detected in the wild until the end of October 2014, but since November 2014 we did not find any significant wave of infection using these family, wiped by the emerge of many other China DDoS new malware families that we detected also afterwards. From the early this year (January 2015), we started to assume the malware popularity and development of .IptabLes|x was stopped..

However, on June 27th 2015 I was informed in the twitter by a friend @TinkerSec for what was suspected as Linux/ChinaZ infection. I supported him with ELF binary sample’s « real time » analysis in twitter as per shown in his report below:

Malware Detection & Analysis – Discovery by @TinkerSec & Analysis by @MalwareMustDie – Consolidated with @Storify – https://t.co/UYO9KDniOr

— Tinker (@TinkerSec) June 26, 2015

Today, our team mate @benkow has detected a shellshock attack with having the same payload as sample, and curiousity made me taking a deeper analysis this time, to find and feel so surprised to realize that the payload is a Linux IptableS or .IptablesX variant actually. I can not believe this myself so I checked many times until I am very positive with this conclusion and after understanding why we were thinking it was Linux/ChinaZ I wrote this information as the follow up, the return of 2014’s DDoS disaster, the IptableS|X threat. Below is the detail.

Lire la suite…

# Modify this file accordingly for your specific requirement.
# http://www.thegeekstuff.com
# 1. Delete all existing rules
iptables -F

# 2. Set default chain policies
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP

# 3. Block a specific ip-address
#BLOCK_THIS_IP="x.x.x.x"
#iptables -A INPUT -s "$BLOCK_THIS_IP" -j DROP
 Lire la suite...