Offensive security
Authorized bug hunting and application, mobile, network, and cloud review focused on access control, authentication, exposed client behavior, and attack paths that can be confirmed.
About GK Data LLC
The person you speak with does the work.
I’m Garrett Kohlrusch, founder of GK Data. I investigate security issues in web applications, APIs, and mobile products, and help small businesses repair, recover, and improve their websites. You work with me from the first conversation through the final handoff.
My research starts with how a system actually behaves: who can access it, what each role can do, and where a control fails. That same attention to detail informs my website work, from a broken contact form to a full rebuild.
Clear work. Direct accountability.
We agree on the work before it starts. You receive a record of what was checked or changed, what remains unresolved, and what to do next. Security testing and website projects each have a scope that fits the job.
Reporting standard
Written authorization, affected roles or assets, reproduction context, demonstrated impact, remediation direction, and stated limitations.
Website repair and care
WordPress stabilization, domain and hosting ownership cleanup, documented accounts, monthly maintenance subscriptions, and practical handoff for small businesses in Blaine, MN and remotely.
Current credentials
01CompTIA Security+
02CompTIA Network+
03IBM Cybersecurity Analyst Specialization
04ITIL 4 Foundation
Public work
Research where disclosure is permitted.
Company and program names appear only where disclosure is public or otherwise permitted. Private evidence and callback details stay out.
NASA GLOBE Observer Stored XSS Case Study
How a mobile observation comment became stored XSS on a public NASA GLOBE web page, with verified impact, root cause, and remediation.
Read the case studyIntigriti 0526: Unintended Stored XSS Bypass
An unintended stored XSS path in Intigriti Challenge 0526 involving unsafe innerHTML, observed SCA Shield bypass behavior, and sink-side remediation.
Read the case studyBlind Stored XSS Through a Text File Upload
How an accepted text file rendered as HTML became blind stored XSS inside an internal review workflow.
Read the case studyStart a conversation
What can I help you with?
Security & website services
Share what you need help with and your timeline. I’ll reply directly about the work, availability, and next steps.