Introducing TREVORproxy and TREVORspray 2.0
Increasing the Speed and Effectiveness of Password Sprays
Password spraying is one of the great joys of pentesting. Or at least, it used to be.
Classically, password spraying has been the single lowest-effort and highest-yield technique for gaining an initial foothold in an organization. This made it pretty fun. You start by gathering up a big list of emails, then you kick off a spray with a stupid password like "Spring2022!", and spend the next ten minutes getting disproportionately large and debatably undeserved hits of dopamine as you discover just how many employees are using that stupid password.
But alas, with increasing Multi-Factor coverage and defensive countermeasures like Smart Lockout, password spraying is becoming more and more of a chore.
As pentesters, we've been forced to dial back the intensity of our password sprays so that they take hours or days to finish. And even when we find a valid credential, it sometimes doesn't lead anywhere thanks to security policies like MFA. Overall, it's a similar upward trend to what's happening in the phishing space, which is a whole different blog post. But I digress.
I suppose that, since we work in cybersecurity, we should be happy about these changes, since it means better security for organizations. After all, the goal of our industry is to make hackers' jobs harder. But since we're hackers and it's our job to hack stuff, it's hard to sit idly by and let our favorite pastime of password spraying go the way of the dodo.
What I'm trying to say is that we're frustrated. And when hackers are frustrated, they write code. So it is with great delight that we are open-sourcing some new tools, which are the product of our frustration, and will hopefully help to make password spraying fun again.
Introducing TREVORproxy and TREVORspray 2.0
When I set out to write these tools, the biggest problem I wanted to solve was Smart Lockout.
Smart Lockout tries to lock out attackers without locking out legitimate users. So basically, it's a fancy word for a lockout mechanism that considers the source IP address when locking an account. There are nuances -- like how Smart Lockout is often powered by machine learning, which makes it inconsistent and unpredictable -- but this is the gist of it.
Smart Lockout at Work
TREVORproxy IPv6 Subnet Proxy Diagram
TREVORproxy is a simple SOCKS proxy that helps avoid Smart Lockout by load-balancing your requests between multiple IP addresses. It accomplishes this with built-in Linux features -- no complex OpenVPN setups or strange firewall configurations. You can use this proxy with Burp Suite, your spraying tool of choice, or even your web browser.
There are two techniques that TREVORproxy can use to spread your requests across multiple IP adressess: an SSH Proxy and a Subnet Proxy.
The SSH Proxy is pretty straightforward. You give TREVORproxy some hosts that support SSH, and it sends your traffic through them, making sure to balance equally between all the hosts.
trevorproxy ssh firstname.lastname@example.org email@example.com
TREVORproxy SSH Proxy Demo
The subnet proxy can be a lot of fun. If you have access to a
/64 IPv6 subnet (Linode is perfect for this), TREVORproxy will load-balance your requests across eighteen quintillion (18,446,744,073,709,551,616) unique source addresses.
Note that if you're using the subnet proxy in IPv6 mode, your target must also support IPv6.
sudo trevorproxy subnet -s dead:beef::0/64 -i eth0
TREVORproxy Subnet Proxy Demo
TREVORspray is a modular password sprayer with built-in TREVORproxy support. It has the following features:
Threads, lots of threads
adfs(Active Directory Federation Services)
custom modules (easy to make!)
Tells you the status of each account: if it exists, is locked, has MFA enabled, etc. (when supported)
Automatic cancel/resume (remembers already-tried user/pass combos in
Automatic infinite reconnect/retry if a proxy goes down (or if you lose internet)
User-Agentand other signatures to look like legitimate auth traffic
--lockout-delaybetween requests to bypass lockout countermeasures
O365 MFA bypass support (disable with
EWS (Exchange Web Services) - Automatically retrieves GAL (Global Address Book)
EAS (Exchange ActiveSync)
EXO (Exchange Online PowerShell)
UM (Exchange Unified Messaging)
AutoDiscover - Automatically retrieves OAB (Offline Address Book)
Azure Portal Access
--reconto list MX/TXT records, O365 tenant info, federation configuration, autodiscover, etc.
TREVORspray Example - O365 Password Spray + MFA Bypass
Note that the eight O365 MFA bypass checks listed above are automatically executed when a valid cred is found.
# --delay Sleep for this many seconds between requests # --lockout-delay Sleep for this many additional seconds when a lockout is encountered # --jitter Add a random delay of up to this many seconds between requests trevorspray -u emails.txt -p 'Spring2022!' --ssh firstname.lastname@example.org email@example.com --delay 30 --lockout-delay 30 --jitter 10
TREVORspray Password Spray + MFA Bypass Demo
TREVORspray Example - Domain Recon
trevorspray --recon evilcorp.com
TREVORspray Domain Recon Demo
By combining the IP-shuffling capability of TREVORproxy and TREVORspray's customizable
--lockout-delay options, you can confuse Smart Lockout and boost the speed and effectiveness of your password sprays. For more examples and in-depth explanations of these concepts, please see the projects' READMEs.