What do Expel and Millennium Corporation sell?

Expel sells Expel MDR and Ruxie. Millennium Corporation sells Zero Trust.

Are Expel and Millennium Corporation in the same category?

They share MDR and managed SOC. Expel's primary category is MDR and managed SOC and Millennium Corporation's is Penetration testing and red team services.

Where are Expel and Millennium Corporation headquartered?

Millennium Corporation is headquartered in Arlington, VA, United States.

Vendor comparison · 2 companies

Expel vs Millennium Corporation

Expel sells managed detection and response (MDR) delivered through its Workbench platform, with 24x7 human analysts working in the security tools a customer already has. Millennium Corporation provides red team operations and cyber training, with clients across the Department of Defense, federal civilian agencies, and the private sector. CISO Tribune files both under MDR and managed SOC. This page sets the two records side by side: what each sells, where it is based, who owns and funds it, the customers it names and its recent news, each fact numbered to its source.

Change the companies

Up to four companies side by side.

Expel
Millennium Corporation

Add a company

Expel vs Millennium Corporation: Products, Customers and Funding Compared
What it sells
	ExpelExpel sells managed detection and response (MDR) delivered through its Workbench platform, with 24x7 human analysts working in the security tools a customer already has.expel.com	Millennium CorporationMillennium Corporation provides red team operations and cyber training, with clients across the Department of Defense, federal civilian agencies, and the private sector.millgroupinc.com
What it sells	Expel MDR^[5][7]A managed detection and response service that works with the security tools a customer already has. Ruxie^[3][5]Expel's AI and automation engine used in its MDR service.	Zero Trust^[7]Adversarial testing of networks to confirm they are Zero Trust.
Categories
Categories	MDR and managed SOC (primary category)	Penetration testing and red team services (primary category) MDR and managed SOC Security consulting and advisory
Headquarters
Headquarters	Not stated on its pages	Arlington, VA, United States^[1][4]
Founded
Founded	Not stated on its pages	Not stated on its pages
Ownership and funding
Ownership and funding	Not stated on its pages	Not stated on its pages
Named customers
Named customers	Not stated on its pages	Not stated on its pages
Recent news
Recent news	Not stated on its pages	Not stated on its pages
G2 and Gartner Peer Insights
G2 and Gartner Peer Insights	G2: listed, seen November 3, 2026^[4] Gartner Peer Insights: Not stated on its pages	G2: Not stated on its pages Gartner Peer Insights: Not stated on its pages
Who it fits
Who it fits	Not written yet	Not written yet
Last verified
Last verified	September 27, 2026	October 30, 2026

Where they overlap

Expel and Millennium Corporation are both filed under MDR and managed SOC.

Where they differ, field by field

Expel's primary category is MDR and managed SOC; Millennium Corporation's is Penetration testing and red team services.
Millennium Corporation is also filed under Security consulting and advisory.
Expel lists Expel MDR and Ruxie. Millennium Corporation lists Zero Trust.
Millennium Corporation is headquartered in Arlington, VA, United States.

What it sells: Expel

What Expel MDR does^[5][7]: Expel MDR provides 24x7 SOC monitoring, with analysts who investigate and respond. Expel says it connects to an existing stack and correlates threats across endpoint, identity, cloud, network, SaaS and more. Expel states a 14-minute mean time to remediate.
What Ruxie does^[3][5]: Expel says Ruxie gathers evidence, enriches alerts and matches patterns in seconds. Expel analysts then investigate and make the critical calls.

What it sells: Millennium Corporation

What Zero Trust does^[7]: Millennium Corporation uses an adversarial mindset to test networks and confirm that they are Zero Trust. The testing checks that users can only access authorized files, that an unauthorized user cannot grant themselves additional permissions, and that the network is constantly validating every user at every interaction.

Questions about Expel and Millennium Corporation

What do Expel and Millennium Corporation sell?: Expel sells Expel MDR and Ruxie. Millennium Corporation sells Zero Trust.
Are Expel and Millennium Corporation in the same category?: They share MDR and managed SOC. Expel's primary category is MDR and managed SOC and Millennium Corporation's is Penetration testing and red team services.
Where are Expel and Millennium Corporation headquartered?: Millennium Corporation is headquartered in Arlington, VA, United States.

About Expel

Expel sells managed detection and response (MDR) delivered through its Workbench platform, with 24x7 human analysts working in the security tools a customer already has. Expel says its service is built so that technology makes it fast and humans make it accurate.^[5]

Expel describes the service as managed detection and response with analysts who can be reached directly over Slack or Teams. Expel says customers connect Workbench to their existing stack, and Expel then correlates threats across endpoint, identity, cloud, network, SaaS and more. Expel says no agents need to be deployed and no rip-and-replace is required.^[5]

Ruxie is the name Expel gives its AI and automation engine. Expel says Ruxie gathers evidence, enriches alerts and matches patterns so that Expel analysts can investigate and make the critical calls. Expel states a 14-minute mean time to remediate for its MDR service.^[5]

Expel Workbench is the platform through which customers see Expel's work. Expel says customers can see every investigation and response in real time inside Workbench.^[5]

Expel says its MDR covers cloud, endpoint, identity, network, SaaS, email and more, across more than 160 technology integrations. Expel names Microsoft, AWS, Google Cloud, CrowdStrike, Okta and Wiz among those integrations.^[5][10]

Expel also offers email threat detection and response, in which Expel says it monitors the email environment 24x7. Expel says this works alongside Proofpoint, Mimecast, Abnormal Security and Sublime. Expel also describes MDR coverage of the AI attack surface, covering attacker use of AI, employee misuse of AI tools and attacks on customer-built AI systems, with detections mapped to MITRE ATLAS.^[6][7]

Expel was started by practitioners. Dave Merkel is co-founder and Chief Executive Officer, Justin Bajko is a co-founder and Chief Strategy Officer, and Yanek Korff is a co-founder and Chief Operating Officer. Greg Notch is Chief Technology Officer.^[8]

2. Expel says Workbench infrastructure runs on GCP and AWS in the U.S, and that alert data is retained up to 15 months, configurable per contract.^[1][2][5][9]

Expel on the record

About Millennium Corporation

Millennium Corporation provides red team operations and cyber training, with clients across the Department of Defense, federal civilian agencies, and the private sector. Millennium Corporation describes its philosophy as anchored around the concept of full-spectrum operations. Millennium Corporation describes itself as a founder-led company.^[2][5]

Millennium Corporation works with the armed services to protect the devices, data, and networks they use. Millennium Corporation helps the Intelligence Community securely collect, analyze, and act on large quantities of data. In federal civilian agencies, Millennium Corporation helps protect highly sensitive and mission critical data. The software engineers of Millennium Corporation craft custom solutions to meet a client's specific needs.

Millennium Corporation analyzes a client's cyber footprint to identify vulnerabilities. Red team assessments from Millennium Corporation normally contain a physical security aspect. During an assessment, Millennium Corporation operators may attempt to physically infiltrate a server room in order to compromise the target organization's network. Millennium Corporation says it has seen through hundreds of assessments that physical security enables cybersecurity and vice versa. Millennium Corporation offers a debrief and report after an assessment has concluded, explaining how its operators infiltrated the client's facility and what the client could have done differently to stop them.^[5]

Millennium Corporation provides red and blue team training, builds cyber ranges, and plays the bad guys as an Opposing Force. Millennium Corporation names k>fivefour as its partner for hands-on cyber operations training for cybersecurity professionals. Millennium Corporation determines how an adversary would most likely attack and then develops protection and training plans. Millennium Corporation sets up and conducts trainings. For in-house trainings, Millennium Corporation helps schedule and track which personnel have received them.^[2][6]

Millennium Corporation uses an adversarial mindset to test networks and confirm that they are Zero Trust. When new systems are added, Millennium Corporation does upfront work to make certain they will integrate with existing systems. Millennium Corporation then tests the new systems to protect them from black hat actors. Millennium Corporation has experience in frameworks such as NIST CSF, RMF, and ISO 27001, and helps clients develop and maintain a GRC program. Millennium Corporation applies red and blue team capabilities and an adversarial approach to attack simulation to protect a client's most valuable assets. Millennium Corporation integrates commercial networking technologies into expeditionary solutions, including a hybrid fiber and wireless network that enables fixed and mobile connectivity.^[7]

Millennium Corporation operates a secure 10,000 sq.ft. facility that includes training and the Cyber Threat Operations Center.^[2][6][7]

Millennium Corporation on the record

Sources

Expel full record

[1]Workbench operations platformExpel · expel.com · published August 5, 2026 · Tier A
[2]Expel announces 20 million in series b fundingExpel · expel.com · undated page, accessed September 27, 2026 · Tier A
[3]Leading managed detection and response (MDR) provider | ExpelExpel · undated page, accessed October 24, 2026 · Tier A
[4]Expel Reviews 2026: Details, Pricing, & Features - G2G2 · undated page, accessed October 24, 2026 · Tier C
[5]Managed Detection and Response Services | Expel MDRExpel · undated page, accessed November 3, 2026 · Tier A
[6]Email threat detection | ExpelExpel · undated page, accessed November 3, 2026 · Tier A
[7]AI attack surface coverage | ExpelExpel · undated page, accessed November 3, 2026 · Tier A
[8]Company | ExpelExpel · undated page, accessed November 3, 2026 · Tier A
[9]Security and compliance support from your MDR | ExpelExpel · undated page, accessed November 3, 2026 · Tier A
[10]Managed Security Solutions | ExpelExpel · undated page, accessed November 3, 2026 · Tier A

Millennium Corporation full record

[1]Millennium corporation expands cyber portfolio by acquiring maxisiq business divisionMillennium Corporation · millgroupinc.com · published May 3, 2023 · Tier A
[2]millgroupinc.comMillennium Corporation · millgroupinc.com · undated page, accessed October 30, 2026 · Tier A
[3]Why Millennium - Millennium CorporationMillennium Corporation · undated page, accessed November 10, 2026 · Tier A
[4]Home - Millennium CorporationMillennium Corporation · undated page, accessed November 10, 2026 · Tier A
[5]Your Guide to Red Team Physical Security Assessments - Millennium CorporationMillennium Corporation · undated page, accessed November 10, 2026 · Tier A
[6]Cybersecurity Training - Millennium CorporationMillennium Corporation · undated page, accessed November 10, 2026 · Tier A
[7]Enterprise Services - Millennium CorporationMillennium Corporation · undated page, accessed November 10, 2026 · Tier A

Spot a factual error? Request a correction.