Reverse Engineering: A Walkthrough for Cybersecurity Challenges

The basics of reverse engineering in the enterprise

Ever wonder how a piece of software actually works when you don't got the source code? It's like trying to figure out a secret recipe just by tasting the soup, which is basically what we do in the enterprise.

In my experience, you can't just trust every third-party app. Reverse engineering helps teams find hidden backdoors or see how an ai agent might be talking to your internal apis.

• Compiled Code: Understanding how binaries behave without the source. For C++, this means looking at machine code disassembly. For Python, since it's bytecode-based, you're usually looking at .pyc files and doing bytecode disassembly or decompilation to get back to something readable.
• Security Audits: Identifying vulnerabilities in legacy retail systems or healthcare software that hasn't been updated in years. (What It Is Legacy EMR and Why It's Blocking Progress in Healthcare)
• Malware Analysis: Breaking down how an attack works to stop it from spreading through the network.

According to the HackTheBox SRMIST guide, this process is vital for learning software internals, especially when dealing with "crackme" challenges or real-world malware.

Most pros use ghidra (thanks nsa) or IDA Pro to read assembly. If you're debugging on windows, x64dbg is the way to go. Honestly, just seeing a graph view in Binary Ninja makes life way easier when tracing logic.

Next, let's look at the actual workflow.

Step by step walkthrough for a binary challenge

So you've got a mysterious binary and no source code. It's like being handed a locked box with no key—but we're gonna pick the lock anyway.

First thing I always do is a "vibe check" using static analysis. You aren't running the code yet, just poking at its guts to see what's inside.

• Strings are gold: Run the strings command. Sometimes developers leave "password123" or internal api keys right in the plain text.
• Identify the entry point: Use a disassembler like ghidra to find the main function. This is where the magic starts.
• Spot the logic: Look for library calls like strcmp (comparing strings) or malloc (allocating memory). If you see strcmp, the program is probably checking your input against a secret key.

Now we actually run the thing, but we do it inside a debugger like x64dbg or gdb so we can freeze time.

• Breakpoints: Set a breakpoint right before a "Wrong Password" message appears. This lets you see what the program is thinking.
• Register flipping: In a ctf, you can often just change a "Zero Flag" in the cpu registers to trick the app into thinking a failed login actually succeeded.
• Memory watching: Watch how the stack changes. In finance apps, you might see how sensitive data is temporarily stored before being encrypted.

Instead of seeing clean code, you're usually staring at something like this in your debugger:

mov eax, [ebp+var_4]
cmp eax, 0x1337
jne loc_401050
push offset aAccessGranted ; "Access Granted"
call _printf

As the HackTheBox guide suggests, mastering these low-level jumps is how you bypass local checks before the agent even hits the network. Honestly, once you bypass your first check, you'll feel like a wizard.

Next, let's talk about more advanced obfuscation.

Reverse engineering for ai agent identity management

So, you've got these autonomous ai agents running around your network, right? Most folks just assume they'll play nice with identity providers like okta or azure entra, but that's a big "if" when you're dealing with custom SCIM (System for Cross-domain Identity Management) implementations. Basically, SCIM is what these agents use to provision themselves or grab permissions from your enterprise directory.

I’ve spent nights reverse engineering how these agents actually handle tokens locally. The connection between the binary and the network is key—the agent's binary execution determines how it requests and stores SAML (Security Assertion Markup Language) assertions to prove its identity to other services. Honestly, it’s a mess—sometimes they ignore expiration dates or leak session data in the logs.

• Token Handling: Use a debugger like gdb to see if the agent is caching scim tokens in plain text within its local memory. If it is, your whole identity governance strategy is basically toast.
• SAML Assertions: I’ve seen agents fail to validate the signature on saml responses. You gotta intercept that traffic to make sure it isn't just accepting any old xml.
• Compliance checks: Frameworks like SOC2 require strict identity auditing. If the agent doesn't log its api calls properly, you can't prove who (or what) did what.

According to pwn.college, mastering these binary internals is the only way to truly understand how software behaves under pressure. It's not just about hacking; it's about making sure your enterprise ai doesn't become a shadow it department.

Next, we're gonna wrap this up by looking at how to automate these security checks.

Automating the boring stuff and real world apps

If you're doing this at scale, you can't manually poke every binary. This is where automation comes in. I usually use the Ghidra Scripting engine (Java/Python) or the Binary Ninja API to write scripts that automatically flag dangerous functions like strcpy or look for hardcoded scim endpoints across hundreds of files.

• Malware and Ransomware: You can't just wait for a patch. Deconstructing ransomware lets you find decryption keys or hardcoded command-and-control IPs.
• Legacy Debt: In industries like healthcare, you're often stuck with software where the original dev left ten years ago. Reversing helps you patch vulnerabilities in systems that don't get updates anymore.
• Zero-Day Defense: When a new exploit hits, you gotta analyze the botnet protocols to see how it moves through your network before it hits your scim or okta integrations.

Using the techniques we talked about from the SRMIST materials, these skills are basically training for real-world problems. Whether you're fixing old retail code or stopping a breach, knowing how to read between the lines of a binary is a total superpower. Stay curious.