Detection rules › Splunk

Windows SqlWriter SQLDumper DLL Sideload

Author
Michael Haag, Teoderick Contreras, Splunk
Source
upstream

The following analytic detects the abuse of SqlWriter and SQLDumper executables to sideload the vcruntime140.dll library. It leverages Sysmon EventCode 7 logs, focusing on instances where SQLDumper.exe or SQLWriter.exe load vcruntime140.dll, excluding legitimate loads from the System32 directory. This activity is significant as it indicates potential DLL sideloading, a technique used by adversaries to execute malicious code within trusted processes. If confirmed malicious, this could allow attackers to execute arbitrary code, maintain persistence, and evade detection by blending with legitimate processes.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1574.001 Hijack Execution Flow: DLL
Privilege EscalationT1574.001 Hijack Execution Flow: DLL
Defense EvasionT1574.001 Hijack Execution Flow: DLL

Event coverage

ProviderEvent IDTitle
Sysmon7Image loaded

Stages and Predicates

Stage 1: search

search (Image="*\\SQLDumper.exe" OR Image="*\\SQLWriter.exe") NOT ImageLoaded="C:\\Windows\\System32\\*" EventCode=7 ImageLoaded="*\\vcruntime140.dll"

Stage 2: fillnull

fillnull

Stage 3: stats

stats BY Image, ImageLoaded, dest, loaded_file, loaded_file_path, original_file_name, process_exec, process_guid, process_hash, process_id, process_name, process_path, service_dll_signature_exists, service_dll_signature_verified, signature, signature_id, user_id, vendor_product

Stage 4: search

search

Stage 5: search

search

Stage 6: search

search `macro`

Exclusions

Top-level NOT(...) conjuncts — predicates this rule actively suppresses.

StageFieldKindExcluded values
1ImageLoadedeq"C:\\Windows\\System32\\*"

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 7 corpus 35 (splunk 35)
Imageeq
  • "*\\SQLDumper.exe"
  • "*\\SQLWriter.exe"
ImageLoadedeq
  • "*\\vcruntime140.dll"

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.