Attackers looking to move sideways inside a network increasingly treat shared file stores, on-prem SMB/CIFS shares, collaboration drives, and cloud file services, as low-risk highways for staging, discovery, and quiet data collection. These locations are attractive because they are widely trusted, broadly accessible, and rarely monitored closely enough to catch subtle behavior. Lateral movement through file shares lets an adversary expand access without noisy scans or obvious remote execution attempts, often succeeding long before defenders notice anything unusual.
How Threat Actors Use Shared Drives
Adversaries use shared drives in several ways. They drop reconnaissance tools, scripts, or encrypted archives into folders where service accounts or administrators will eventually access them. They hide tooling inside harmless-looking filenames or deeply nested folders and rely on routine user actions to trigger execution or movement. When cloud storage is available, attackers can shift staging and exfiltration into remote accounts under their control, which makes detection even more difficult. This fits into the broader pattern of living off trusted services instead of relying on noisy exploits.
Why Shared Drives Work Well for Quiet Lateral Movement
Shared drives are busy environments by design. Users copy files constantly, sync folders across devices, and run automated tasks that generate steady background noise. That noise makes it easy for attackers to hide small deviations, such as a new executable or a large archive dropping into a common folder. Weak permissions, legacy share configurations, and wide write access contribute to the problem. In hybrid environments, attackers can also pivot between on-prem shares and cloud collaboration drives, where trust models differ and oversight is inconsistent.
Common Techniques Observed
A typical attack path looks like this: foothold on a workstation, reconnaissance to locate writable or commonly accessed shares, staging of scripts or payloads, and then using legitimate processes, scheduled tasks, sync tools, backup software, or service accounts, to move code or credentials deeper into the environment. Credential theft often plays a supporting role. Once an attacker captures usable tokens or hashes, they can access more shares and deploy more staged tools without generating obvious red flags. Because the approach blends in with normal behavior, dwell time increases and response becomes harder.
Detection Challenges
Catching this activity is difficult because file creation, movement, and deletion events are high volume and rarely filtered with security in mind. Many environments forward these events into logging platforms without linking them to identity or process behavior, which reduces visibility and increases fatigue. Successful detection usually requires establishing baselines: who normally writes to a given share, which processes interact with shared folders, and how service accounts move across systems. Attack-path mapping also helps, since the relationships between identities, hosts, and shares often reveal the routes attackers prefer.
Practical Mitigations That Reduce Risk
Risk drops considerably when organizations strengthen access control, tighten permissions, and improve visibility around shared storage.
Start with access cleanup. Remove broad write rights, restrict legacy shares, and review service accounts that touch multiple systems. Enforce secure authentication where possible and, for cloud drives, monitor third-party app consents and permissions granted to automation tools. File integrity monitoring helps when paired with process and identity telemetry, because an unexpected write by a rarely used account or a desktop process writing archives to a server becomes much harder to overlook.
Combine this with attack-path analysis. Understanding how users, groups, and systems connect makes it easier to predict the lateral routes an attacker would choose. Treat shared drives as part of the identity surface rather than just storage, and aim for monitoring that ties file events to real user behavior. Tabletop exercises focused on file-based staging can uncover operational blind spots before a real attacker finds them.
What To Do When You Find Staging Artifacts
If you discover suspicious files or scripts on a shared drive, start with containment and context. Limit access to the affected share or narrow the permissions used to drop the artifact. Capture metadata, timestamps, ACLs, and the host that created or modified the file, and search for similar files across other shares. Check account activity around the time of the write and look for related scheduled tasks, process launches, or signs of credential misuse. Preserve evidence before cleaning anything up and coordinate with system owners to avoid breaking legitimate workflows. These steps help determine how far the attacker progressed and whether other systems have been touched.
Balancing Operations and Security
Hardening shared filesystems often requires cooperation across storage teams, identity teams, and security teams. Start with the highest-risk shares and accounts, and phase changes carefully so you don’t disrupt business operations. Improving telemetry and conducting regular threat hunts focused on file-based staging will shorten dwell time and reduce the chance that an attacker uses shared drives as a quiet highway through the network.
How Can Netizen Help?
Founded in 2013, Netizen is an award-winning technology firm that develops and leverages cutting-edge solutions to create a more secure, integrated, and automated digital environment for government, defense, and commercial clients worldwide. Our innovative solutions transform complex cybersecurity and technology challenges into strategic advantages by delivering mission-critical capabilities that safeguard and optimize clients’ digital infrastructure. One example of this is our popular “CISO-as-a-Service” offering that enables organizations of any size to access executive level cybersecurity expertise at a fraction of the cost of hiring internally.
Netizen also operates a state-of-the-art 24x7x365 Security Operations Center (SOC) that delivers comprehensive cybersecurity monitoring solutions for defense, government, and commercial clients. Our service portfolio includes cybersecurity assessments and advisory, hosted SIEM and EDR/XDR solutions, software assurance, penetration testing, cybersecurity engineering, and compliance audit support. We specialize in serving organizations that operate within some of the world’s most highly sensitive and tightly regulated environments where unwavering security, strict compliance, technical excellence, and operational maturity are non-negotiable requirements. Our proven track record in these domains positions us as the premier trusted partner for organizations where technology reliability and security cannot be compromised.
Netizen holds ISO 27001, ISO 9001, ISO 20000-1, and CMMI Level III SVC registrations demonstrating the maturity of our operations. We are a proud Service-Disabled Veteran-Owned Small Business (SDVOSB) certified by U.S. Small Business Administration (SBA) that has been named multiple times to the Inc. 5000 and Vet 100 lists of the most successful and fastest-growing private companies in the nation. Netizen has also been named a national “Best Workplace” by Inc. Magazine, a multiple awardee of the U.S. Department of Labor HIRE Vets Platinum Medallion for veteran hiring and retention, the Lehigh Valley Business of the Year and Veteran-Owned Business of the Year, and the recipient of dozens of other awards and accolades for innovation, community support, working environment, and growth.
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