Server Software Component: vSphere Installation Bundles T1505.006

Tactic: Persistence

Adversaries may abuse vSphere Installation Bundles (VIBs) to establish persistent access to ESXi hypervisors. VIBs are collections of files used for software distribution and virtual system management in VMware environments. Since ESXi uses an in-memory filesystem where changes made to most files are stored in RAM rather than in persistent storage, these modifications are lost after a reboot. However, VIBs can be used to create startup tasks, apply custom firewall rules, or deploy binaries that persist across reboots. Typically, administrators use VIBs for updates and system maintenance.

Authoring guide

Patterns shared across the 1 rule above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (2 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
Message1contains 1 image profile bypassing signing and acceptance level..., image profile with validation disabled. , vib without valid signature,
sourcetype1in 1vmw-syslog, vmware:esxlog*

Top indicator values (5 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.

FieldKindValueRules (here)Corpus reach
Messagecontains
image profile bypassing signing and acceptance level verification.
1
Messagecontains
image profile with validation disabled.
1
Messagecontains
vib without valid signature,
1
sourcetypein
vmw-syslog
123
sourcetypein
vmware:esxlog*
123

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Platform (all)
Domain (all)

Splunk 1 rule