Supply Chain Weaknesses – Other People’s Weaknesses Are Cybercriminals’ Opportunities

Introduction

Let me paint you a picture. You have the latest firewalls, endpoint security in place, tokenized data, staff trained on the signs of phishing — then your network is compromised. How? An HVAC vendor logging into your crown jewels (read: your manufacturing network) with a password123 username and password combo.

It’s frustrating. And dangerous. The blind backdoor is a third party nearly every time: the vendors, suppliers, or partners you relied on to reach into your environment. In over 30 years of messing with networks (from routers humming in server racks to manual configuration of muxes for PSTN voice data), I’ve seen this replay dozens of times.

And here’s the rub: These days, as manufacturing companies increasingly rely on complex, interconnected supply chains, the attack surface is enormous. With that being said, hackers certainly don’t have to kick down your front door — why would they? Instead, they’ll just hop a ride through your vendor’s not-secured server instead.

Let’s discuss how these attacks take place, why you are vulnerable to them and — yeah — what you can do about it.

The Anatomy of Supply Chain Attacks

I’ll give hackers this point: they are creative. They’ll take advantage of the weakest link in your network, even if it’s not your network. Here’s how it plays out:

1. Discovering Weaknesses in Third Party Systems

In this series, I explain why it’s important for an executive to be aware of how your vendors, suppliers, and partners are presumably profiled by attackers. An outdated ERP system here. An unmanaged Active Directory at that location. Not even a vendor with VPN connections stapled to a sticky note.

2. Gaining Initial Access:

• Email phishing attacks on vendor employees.
• Abuse of forgotten software flaws in vendor systems.
• Credential stuffing (one vendor likely reuses his Netflix password on your systems).

3. Pivoting Into Your Network:

Once an attacker gets into a vendor, the fun begins. They exploit that weak link, using it as a link in the chain — often abusing trusted relationships between your organization and the vendor. Without adequate segmentation, think RMM (Remote Monitoring & Management) software.

4. To Install Malwares on Several Systems:

From there? Droppers, remote access trojans (RATs), or good old ransomware. By now they’re in your environment — perhaps exfiltrating intellectual property or sabotaging your production line.

This whole chain isn’t a theoretical exercise. I see versions of it happen — far too often, unfortunately — especially in manufacturing supply chains that depend on multiple vendors to connect critical systems.

Real-World Examples

Example #1 – The NotPetya Disaster

But who will forget NotPetya in 2017? (I remember how I rushed, along with my team, to piece it all together—pure chaos.) Massive companies were brought to their knees because they were using a third-party accounting package (MeDoc). Hackers compromised the software vendor and pushed nefarious updates to customers, weaponizing trust, in effect.

Example #2 – Vendor VPN Exploit

One case I dealt with involved a food manufacturer whose supplier was still running a VPN solution that had not been patched for vulnerabilities since 2015. Attackers compromised the vendor’s login credentials and boom — pivoted right into the manufacturer’s OT network. Machines were frozen for days, costing millions in lost inventory.

Example #3 – It Looks Just Like What I Saw Last Week

I will not name names (NDA life), but just recently I reviewed a setup for a manufacturing company in which no fewer than 15 different vendors had real-time access to production systems. Many of them used outdated VPN login info, and — get this — all of it went unmonitored in real time. It was like a buffet laid out for attackers. What do you think my 1 recommendation was? Yes: zero-trust segmentation and frequent vendor audits.

Quick Take

For the short of time (who likely scrolled straight down here):

• Your vendors and suppliers are parts of your attack surface.
• It’s important to note that most supply chain breaches begin with phishing or outdated software.
• Periodic vendor assessments aren’t a luxury — they’re a necessity.
• Adopt zero-trust architecture (assume breach, minimize trust).

Risk Management

The road to securing your supply chain begins by coming to a hard truth, though: You don’t control your vendors’ security hygiene. But you can control the risk associated with this dependence. Here’s how:

Vendor Risk Assessment 101:

• Due Diligence: Through some level of due diligence, ensure the vendor is cybersecurity-compliant before onboarding. Do they conduct routine scans for vulnerabilities? Are their employees trained on phishing?
• Documented Policies: Have agreements in place with third parties that detail how they manage security, incident response, and the data they access.
• Tiered Access: Not all vendors require the same level of access. Some might only need file-sharing privileges; others, access to OT systems. Assign permissions sparingly.

Monitor, Monitor, Monitor

• Audit Logs: Keep an eye on who accessed what, when, and from where. Believe me, nothing will bring a red flag up faster than a strange login at 3 a.m. from Romania when your vendor has his roots in Delhi.
• Vendors Endpoint Monitoring: Apply monitoring solutions for vendor endpoints accessing sensitive systems. It’s your environment they’re getting intimate with — behave like it.

Rapid Vendor Termination:

• Why It Matters: You need the ability to instantly cut a vendor’s access if you suspect a breach. The last thing you want is an attacker using a compromised third party as a persistent foothold.

Creating Resilient Supply Chains

Segmentation: Never Trust, Always Verify

Zero-trust is the hot buzzword we’re all throwing around (I spent half of my last DefCon session going on a rant about the overuse of “AI security,” but that’s another blog). But the principle of it? Solid. It boils down to:

• Trust no one. Verify everyone.
• Only give the least privilege access. If a vendor requires only read-only permissions, don’t give them write access “just in case.” “Three banks I’ve assisted in implementing zero-trust architectures recently—it wasn’t easy, but it was bloody essential.”

Ensure Data Transfers Between Vendors Are Encrypted

My rule? Ensure your network and vendors encrypt all traffic between the two. Always. And even if no one is actually sniffing your pipes (yet), encryption removes unnecessary risk.

Crisis Simulations

Rehearse breach scenarios with relevant third parties. What if Vendor A gets hit with ransomware that infects you? How quickly can you contain and respond? Rehearsal makes perfect — and, more crucial, averted disaster.

Be Wary of Vendor-Suggested AI-Powered Tools

There’s a hot take for you — I do not trust third-party vendor AI-driven solutions. Too many unproven algorithms, black-box decision-making, and false positives. The buzzwords won’t save you. Concentrate on proven practices such as network segmentation and enforced access controls.

Final Thoughts

Supply chain attacks are not going away. They’re actually just starting to hit their stride, as interdependent and tech-hungry have supply chains become — particularly in industries like manufacturing.

But don’t panic. The challenges are substantial, but solutions are relatively simple when approached thoughtfully: careful vendor evaluation, well-thought-out segmentation, effective monitoring, and zero-trust.

Keep in mind that you are only as strong as the weakest link. So, don’t allow that link to be a third party entering your network unchecked.

And if you’ll excuse me now, I’m off for another coffee before heading into the next client review — another manufacturing setup filled with vendor sprawl. Until then, keep your heads and eyes up.