kevmap

TechniquesT1491.002 › AN1623

AN1623 Analytic 1623

Linux · attack.mitre.org · ATT&CK Enterprise v19.2

<p>Adversary compromises a Linux-based web server and modifies hosted web files by exploiting upload vulnerabilities, remote code execution, or replacing index.html via SSH/webshell.</p>
Detects
T1491.002 External Defacement
Part of
DET0590 Behavioral Detection of External Website Defacement across Platforms

Log sources and channels

Exactly as MITRE states them in x_mitre_log_source_references. Where a channel is vague, it is vague in the source; kevmap does not tidy it.

Log sourceChannelData component
auditd:SYSCALLopen/write syscalls targeting web directory filesDC0061 File Modification
NSM:ConnectionsSuccessful sudo or ssh from unknown IPsDC0088 Logon Session Metadata
NSM:FlowSuspicious POSTs to upload endpointsDC0085 Network Traffic Content

Mutable elements

Parameters MITRE marks as environment-specific. These are the knobs you are expected to tune; they are why an analytic is not a rule.

FieldDescription
web_rootMay differ (e.g., /var/www/html, /srv/http, etc.)
payload_hashAdversary content hash may change across campaigns
UserContextCan range from apache/nginx user to root if escalated

KEV CVEs whose mapped technique this analytic detects

CVEVendor / productState
CVE-2018-15961Adobe ColdFusionMapped