Siemens S7 Series PLCs (AA26-231A) Campaign

Technique ID

Technique Name

Detection Strategy

T1595

Active Scanning

Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate...

T1190

Exploit Public-Facing Application

Adversary sends crafted HTTP/S (or other service) input to an Internet-facing app (IIS/ASP.NET, API, device portal). Chain: (1) abnormal request patterns to public endpoint → (2) elevated 4xx/5xx or unusual methods/paths → (3) server process (w3wp.exe/other service) spawns shell/LOLbins or loads non-standard modules → (4) optional outbound callback from the host/container. Adversary exploits Apache/Nginx/app servers. Chain: (1) suspicious requests in access logs → (2) spike of 5xx or WAF blocks → (3) web server or interpreter (apache2/nginx/php-fpm/node/python) spawns /bin/sh, curl, wget, socat, or writes webshell → (4) outbound callback.

T1036

Masquerading

Adversary renames LOLBINs or deploys binaries with spoofed file names, internal PE metadata, or misleading icons to appear legitimate. File creation is followed by execution or service registration inconsistent with known usage. Adversary drops renamed binaries in uncommon directories (e.g., /tmp, /dev/shm) or uses special characters in names (e.g., trailing space, Unicode RLO). Execution or cronjob registration follows shortly after file drop.

T1219

Remote Access Tools

Chain of remote access tool behavior: (1) initial execution of remote-control/assist agent or GUI under user context; (2) persistence via service or autorun; (3) long-lived outbound connection/tunnel to external infrastructure; (4) interactive control signals such as shell or file-manager child processes spawned by the RAT parent. Sequence of RAT agent execution, systemd persistence, and long-lived external egress; optional interactive shells spawned from the agent.