Ahmed Sultan, widely known in the security community by the handle 0x4148 and other online aliases, is a cybersecurity professional and security researcher with more than 16 years of experience, primarily focused on offensive security, red teaming, security engineering, exploit research, vulnerability research, and bug bounty.
He is a Co-Founder of DeXpose and currently leads Security Engineering and Red Team at Callsign. Earlier in his career, Ahmed worked with the EG-CERT Red Team, gaining hands-on experience in advanced penetration testing, adversary simulation, and national-level cybersecurity operations. He also co-founded RedForce, where he worked extensively on red teaming, penetration testing, and offensive security research. Across his career he has worked with a range of other cybersecurity firms on offensive security engagements, and has been active in bug bounty programs, finding and reporting vulnerabilities across a wide variety of targets.
His work focuses on offensive security, adversary techniques, vulnerability research, threat intelligence, and real-world security engineering.
Focus
- Offensive security
- Red teaming
- Security engineering
- Exploit research
- Vulnerability research
- Bug bounty
- Threat intelligence
Certifications
- Red Team Lead
- CRTO
- OSEP
- OSWE
- OSCE
- OSCP
- GXPN
- GCPN
- GDAT
- GSLC
- GWAPT
- eCPTX
- eWPTX
- eCRE
- among others
Education
Master’s degree in Information Security