Adversaries may transfer tools or other files between systems in a compromised environment. Once brought into the victim environment (i.e., Ingress Tool Transfer) files may then be copied from one system to another to stage adversary tools or other files over the course of an operation.
Adversaries may copy files between internal victim systems to support lateral movement using inherent file sharing protocols such as file sharing over SMB/Windows Admin Shares to connected network shares or with authenticated connections via Remote Desktop Protocol.(Citation: Unit42 LockerGoga 2019)
Files can also be transferred using native or otherwise present tools on the victim system, such as scp, rsync, curl, sftp, and ftp. In some cases, adversaries may be able to leverage Web Services such as Dropbox or OneDrive to copy files from one machine to another via shared, automatically synced folders.(Citation: Dropbox Malware Sync)
Detection Strategy for Lateral Tool Transfer across OS platforms
Filter Network Traffic: Employ network appliances and endpoint software to filter ingress, egress, and lateral network traffic. This includes protocol-based filtering, enforcing firewall rules, and blocking or restricting traffic based on predefined conditions to limit adversary movement and data exfiltration. This mitigation can be implemented through the following measures:
Ingress Traffic Filtering:
Egress Traffic Filtering:
Protocol-Based Filtering:
Network Segmentation:
Application Layer Filtering:
Network Intrusion Prevention: Use intrusion detection signatures to block traffic at network boundaries.