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mckesson.com Domain Breach Exposure Report

Risk Score

High Risk

Massive event volume or critical assets compromised.

AI Findings Summary

Critical

The telemetry indicates a significant exposure event for McKesson, with over 100,000 recorded incidents between July 2025 and June 2026. The vast majority of these events, over 96,000, are classified as historical data breaches, while approximately 4,100 are active infostealer logs. Employee credentials appear to be the primary target, with 88,985 employee-related events, followed by 11,427 client-related events. Malware families such as Redline, LummaC2, and Rhadamanthys are prevalent in the infostealer logs, suggesting credential harvesting and potential further compromise. The data breaches and infostealer activity are concentrated on McKesson's portal and connection services, including mms.mckesson.com and connect.mckesson.com, primarily impacting users in the United States.

Total Events

100,412
credential exposure events

Employee Affected Events

88,985
account email domain = mckesson.com

Client Affected Events

11,427
service target = mckesson.com

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12-Month Events Timeline

Event volume by breach date, employee VS client

EmployeesClients
50,00033,33316,6670
peak month 40,063
Jul 25Sep 25Nov 25Jan 26Mar 26May 26Jun 26

Infostealers VS Data Breaches

Live stealer logs VS data breaches

Infostealer logs
Events4,130
Share4%
Data breaches
Events96,282
Share96%
Infostealer logs (4%)
4,130events
Data breaches (96%)
96,282events

88,985 compromised employee accounts pose an infrastructure risk, while 11,427 leaked client credentials create regulatory liability.

Antivirus Distribution

Security Tools on Infected Endpoints

Windows Defender68
Windows Defender McAfee VirusScan7
McAfee5

Malware Families Distribution

Distribution of Active Stealer Strains

Redline2,052
LummaC2678
Rhadamanthys205
Vidar188
X-Files116
Acreed99
Blank Grabber27
StealC8
Millenium7

Top Login URLs

Top exposed services found in the event results

  1. 1mckesson.com1,538
  2. 2https://portal.mms.mckesson.com/login739
  3. 3https://mms.mckesson.com/portal/login501
  4. 4portal.mms.mckesson.com/login387
  5. 5mms.mckesson.com/portal/login307
  6. 6https://mms.mckesson.com288
  7. 7mms.mckesson.com287
  8. 8https://connect.mckesson.com/signin268
  9. 9https://connect.mckesson.com155
  10. 10connect.mckesson.com148

Infostealer By Geography

Shows the distribution of Infostealer-related credential exposure events across different geographic regions. The location is determined by analyzing the metadata of the infected machines associated with each event.

United States
Events1,599
Netherlands
Events404
Germany
Events402
Denmark
Events165
Philippines
Events106
Canada
Events92
India
Events91
France
Events51

Country Breakdown

  1. 1United States1,599
  2. 2Netherlands404
  3. 3Germany402
  4. 4Denmark165
  5. 5Philippines106
  6. 6Canada92
  7. 7India91
  8. 8France51

Services Classification Distribution

Blast radius - closer to core = more critical infrastructure, size = credential volume

Microsoft313
Citrix143
Okta91
Pulse Secure85
Jira (Atlassian)58
FortiNet VPN19
Git18

Operating System Distribution

Distribution of compromised endpoint builds

Windows 11363
Windows 11 Pro (10.0.26120) x64153
Windows 11 Home (10.0.26100) x64146
Windows Server 2012 R2 x32137
Windows Server 2016 x32137

Leak Repository Classification

Where the exposed records currently reside

0
Named breaches
49,184
Combolist pools
47,098
Unattributed dumps

Disclaimer: This report includes AI-generated content. AI can make mistakes, so verify important findings independently before taking action.