Last Updated: 2018-01-07 22:02:31 UTC
by Renato Marinho (Version: 1)
In the last couple of days, we received some reports regarding a malicious campaign which is deploying Monero cryptocurrency miners on victim’s machines. After analyzing a compromised environment, it was possible to realize that a critical Oracle WebLogic flaw, for which the exploit was made public a few days ago, is being used.
The vulnerability (CVE 2017-10271)  is present in WebLogic Web Services component (wls-wsat) and, due to improperly user input sanitizing, it may allow an unauthenticated remote attacker to execute remote arbitrary commands with the privileges of the WebLogic server user.
The exploit is pretty simple to execute and comes with a Bash script to make it easy to scan for potential victims. The test script basically checks for the string “Web Services” while accessing the URL <HOST>/wls-wsat/CoordinatorPortType, as seen in the image below.
Figure 1 - Vulnerability check
The vulnerability affects supported versions 10.3.6.0.0, 126.96.36.199.0, 188.8.131.52.0 and 184.108.40.206.0 and, at least, the unsupported version 10.3.3.0.
The dropper script used in this campaign, additionally to download and execute the miner, [accidentally] kills the WebLogic service on target machine – and this may have alerted some victims. In Figure 2, a screenshot of part of the script where "pkill" command is called with the argument "$mName", which value was set to "java" at the beginning of the script. So, killing "java" means killing WebLogic as well.
Figure 2 – Script killing “java”
In this case, the campaign objective is to mine cryptocurrencies, but, of course, the vulnerability and exploit can be used for other purposes. Check your environment for this vulnerability and, if necessary, apply the patches as soon as possible.
It is also recommended that you check if a vulnerable environment may have been already compromised. Analyse carefully processes with a high and constant CPU consumption.
Additionally, try to find rogue cryptocurrencies miners in your network by correlating the network traffic with the new (beta) SANS ISC feed, which contains IP addresses of miner pools .
The indicators for this specific campaign are listed below.
IOCs (Indicators of Compromise)
We noticed that IP address 220.127.116.11 was both the source of the attacks and the repository of cryptocurrencies miner’s binaries.
Special thanks to Diego Piffaretti and Victor Matuk for collaborating with me on this analysis.
Last Updated: 2018-01-05 17:05:30 UTC
by John Bambenek (Version: 2)
By now, you've heard about the processor vulnerabilities affecting almost every processor in common use today; those vulnerabilities are called Meltdown and Spectre.
The only common platform that seems unaffected as of the current moment are iPhone/iPads (Removed per recent advisory).This bug is probably worth its name and logo considering the pervasive nature of the vulnerability. At its core, both involve kernel issues that can lead to leaking running memory outside the current process which can involve compromises of system confidentiality (think encryption keys, passwords, PII/NPI in memory, etc). Contrary to some initial reporting, this is NOT just an Intel bug, it affects AMD and ARM processors as well. These could even be used in cloud / virtualized environments to leak memory outside the running virtual machine. It involves a flaw in "speculative execution" common in these processors where, in the right conditions, code can trick the processor in leaking data returned from other applications.
Below are advisories of most of the relevant companies. The patches should be considered preliminary to protect against the most obvious paths to this vulnerability, but future patches are likely planned to deal with the potential significant performance hits from these patches and for better mitigation coverage. Spectre, in particular, will require follow-on patching. Due to the nature of these patches, reboots will be required. So in the short term, patch and reboot everything.
|Intel||Security Advisory / Newsroom|
|Project Zero Blog|
|MITRE||CVE-2017-5715 / CVE-2017-5753 / CVE-2017-5754|
|Red Hat||Vulnerability Response|
The good news is patches are out for almost everything (Microsoft has moved up their monthly patching up a week to today, more on that in a different post). The bad news is, Spectre, in particular can't be completely mitigated by patching as it seems it will require a hardware fix. The good news is that Spectre is harder to exploit.
Firefox's initial testing has shown it is possible to trigger these flaws remotely via web content, so devices that browse the web or execute external content are particularly vulnerable (in particular, malware sandboxes are of a concern to me here which by design are unpatched operating systems). Otherwise, you have to find some way to execute code on the victim machine. The bad news is, the fixes can slow down your devices with some initial (disputed) reporting of an up to 30% performance hit to the CPU.
IoT devices are, again, of particular weakness. They run these same processors but as we know, most consumers never use whatever limited interface to update the devices even when it is necessary, and in this case, more than one update cycle may be required.
The best mitigation may be to put these devices in the snow in the street in front of your house and let the plows take care of them. For most IoT devices, getting code running on the device that exploit these flaws will be non-intuitive but that will vary by device. My biggest concern is that someone uses this vulnerability in a controlled environment to find flaws in specific IoT devices (or even default passwords), to create the next Mirai.
So while the advice is "patch now", the problem we will be grappling with is the performance hits (this will be brutal for cloud vendors especially if it's on the scale of 30%) and the follow-on disruptive patching this will require in the coming months.
No known exploitation for this is occuring in the wild, but that will change in the next few days. This dairy will be updated as the situation warrants.
UPDATE 1536 UTC (Bambenek) - Microsoft is actually filtering systems that have not certified compatability with the updates, that means if you are running an anti-virus / endpoint product Microsoft have listed as "safe" you will not get the update. This is designed to prevent BSOD issues. Working on trying to find a good listing of which products are "safe" or not.
UPDATE 1625 UTC (Bambenek) - Microsoft is only releasing the update for these vulnerabilities early, and then only for a partial subset of Windows Operating Systems.
UPDATE 2017-01-05 1700 UTC (Bambenek) - Added Apple advisory, iPhone/iPad devices are affected via Safari/web-browsers.
bambenek \at\ gmail /dot/ com