Security Monitoring & SIEM Analyst

Security Monitoring & SIEM Analyst
Location: Berkshire (Onsite)
Salary: 45,000 - 60,000 + excellent benefits & training
Security Clearance: Ideally SC Cleared or eligible for SC (UK Nationals only)

Company Overview
An exciting opportunity to join a global technology organisation with a well-established cyber security capability supporting mission-critical environments.
Cyber security is central to the organisation's strategy, with ongoing investment in tooling, threat intelligence, and specialist talent. The security function operates at a mature level, combining Security Operations, threat detection, incident response, and continuous improvement practices to defend against evolving threats.

Role Overview
As a Security Monitoring & SIEM Analyst, you will play a key role within the Security Operations function, focused on real-time detection, investigation, and response to cyber threats using SIEM and security tooling.
This role combines hands-on SIEM analysis, alert triage, investigation, and detection improvement, alongside exposure to incident response and proactive threat detection activities.
You will work across multiple data sources to identify suspicious behaviour, analyse events, and support the organisation's cyber defence posture through effective monitoring and rapid response.

Key Responsibilities
Monitor, analyse, and investigate security alerts across SIEM and security tooling
Conduct detailed investigations across log, endpoint, identity, and network telemetry
Develop and optimise detection logic and SIEM queries to improve alert fidelity
Analyse security events and correlate activity across multiple data sources
Support incident response activities, including containment, escalation, and remediation
Perform IOC analysis, enrichment, and validation using threat intelligence sources
Identify gaps in detection capabilities and contribute to continuous improvement
Work closely with infrastructure, SOC, and incident response teams to enhance response capability
Produce clear and structured investigation reports and escalation summaries

Skills & Experience Required
Core SIEM & Detection Skills
Strong knowledge of SIEM platforms (e.g. Microsoft Sentinel, Splunk, Elastic)
Experience writing and tuning queries using:
o Kusto Query Language (KQL)
o ES QL / Kibana Query Language
o Splunk SPL
Understanding of event correlation, alerting, and detection use-case development

Technical Foundations
Strong knowledge of:
o Linux and Windows operating systems
o Core networking concepts (TCP/IP, DNS, HTTP/S, firewalls, VPNs)
Experience analysing logs across:
o Endpoint, identity, network, and cloud environments

Threat Detection & Security Tooling
Strong knowledge of:
o EDR/XDR concepts and workflows
o IDS/IPS technologies and signature-based detection
Experience working with tools such as:
o Microsoft Defender, CrowdStrike, SentinelOne, or similar

Threat & Adversary Knowledge
Understanding of attacker Tactics, Techniques and Procedures (TTPs) and how they manifest in logs and telemetry
Familiarity with MITRE ATT&CK framework
Evidence of staying up to date with:
o Emerging threats
o Adversary tradecraft
o Defensive techniques

Incident Handling & Investigation
Experience handling security incidents through:
o Detection and triage
o Investigation and analysis
o Handover to Incident Response teams
Strong understanding of:
o Incident management processes
o Host-based forensic concepts
Ability to apply post-incident review (PIR) learnings to improve detection and response

Desirable Experience
Experience within a SOC or cyber defence environment
Exposure to threat hunting or detection engineering
Experience in high-security or regulated environments

Certifications (Beneficial)
Microsoft SC-200 (Security Operations Analyst)
GIAC / SANS certifications (GCIH, GCIA, GCED, etc.)
CREST (CPIA, CRIA, CCTIA, CCBTP)
Other recognised cyber security certifications

Why Join?
Work within a mature Security Operations environment
Exposure to advanced SIEM tooling and large-scale environments
Strong investment in training, certifications, and progression
Opportunity to develop into:
o Senior SIEM Analyst
o Detection Engineer
o Threat Hunter


About Adecco
Adecco is acting as an Employment Agency. We are proud to be an equal opportunities employer. We are on the client's supplier list for this role.