====== Memory-Only Malware ======

===== Definition =====
Memory-Only Malware is a malware or detection concept used to interpret code behavior, suspicious execution, defensive telemetry, or incident response findings.
In a forensic report, memory-only malware should be treated as a source of evidence and uncertainty, not as a shortcut to intent. The useful question is what the record supports, what it does not support, and what another source says when asked the same question.

===== Background =====
Malware analysis is where tools can be brilliant and still not know what the evidence means. A rule hit is a lead, not a courtroom verdict with better syntax highlighting.
A reviewer should be able to follow the claim from source evidence to cautious conclusion without spelunking through unsupported confidence. A YARA hit is a lead, not a tiny conviction wearing curly braces.

===== Technical Description =====
Review compares static properties, dynamic behavior, memory evidence, process lineage, persistence records, network traffic, and detection-rule context.
If the tool normalized, decoded, or reconstructed the record, that transformation belongs in the notes.

===== Forensic Relevance =====
  * **User activity review:** It may support account or profile context, but only when independent artifacts point the same direction.
  * **Contradiction testing:** It is useful for finding places where logs, metadata, storage behavior, or accounts disagree.
  * **Reporting decisions:** It helps decide how narrow the finding should be when memory-only malware looks interesting but not conclusive.
  * **Timeline reconstruction:** Memory-Only Malware can help place activity in sequence when the time source and collection conditions are understood.
  * **Recovery analysis:** It can explain why data was recovered, missed, corrupted, or only partially reconstructed.

===== Evidence Sources =====
^ Evidence source ^ What it may show ^ Reliability limits ^ What it cannot prove alone ^
| Memory image | May show processes, sockets, injected regions, handles, and volatile keys. | Collection timing and acquisition quality define what survives. | Does not show what was never resident. |
| Process and module lists | May support execution and loaded-code context. | Malware can hide or corrupt views. | Do not prove user intent. |
| Network sockets | May show live communication context. | Connections can close quickly and attribution needs process support. | Do not prove content or motive. |
| Endpoint telemetry | May corroborate live response observations. | May be filtered, delayed, or absent. | Does not replace source evidence. |

===== Interpretation Limits =====
The most common error is treating memory-only malware as proof of motive. It may support a technical event, a sequence, or a contradiction, but motive needs stronger ground.
Another bad leap is treating absence as intent. Missing data can come from retention, configuration, collection scope, sync behavior, overwriting, media behavior, or ordinary use.
A tool result should be described as a parsed or recovered record, not as the tool's opinion about what happened. Tools surface evidence; they do not understand it.
A YARA hit is a lead, not a tiny conviction wearing curly braces.

===== Common Misinterpretations =====
  * Assuming sandbox behavior matches production behavior.
  * Treating packing or obfuscation as attribution.
  * Ignoring false positives because the alert name sounded expensive.
  * Treating memory-only malware as proof that a specific user acted, when the artifact only supports system or account context.
  * Treating a timestamp as exact truth without checking timezone, clock drift, and source semantics.

===== Example Scenario =====
A responder notices memory image that appears to line up with a disputed timeline.
The artifact may explain part of the sequence, but ordinary system behavior still needs to be ruled in or out.
The analyst preserves the source, exports the relevant records, checks process and module lists, and documents what remains unresolved.

===== Analysis Workflow =====
  - Define the question before opening another parser: what should Memory-Only Malware help answer?
  - Preserve the source evidence and document how the memory image was collected.
  - Record tool versions, input paths, output paths, time settings, and errors.
  - Identify observed facts before writing any interpretation.
  - Normalize time sources and document timezone, clock drift, and collection-time effects.
  - Compare at least two independent artifact families before raising confidence.
  - Consider benign explanations, automated behavior, retention, sync, and storage-device behavior.
  - Write conclusions proportionally: observed fact first, inference second, uncertainty always visible.

===== Reporting Guidance =====
Reporting on memory-only malware should be precise enough that another analyst can retrace the claim without inheriting the original examiner's confidence.
Avoid wording that converts possibility into intent. The report should not say a user deliberately deleted, hid, wiped, or tampered with evidence unless the evidence actually supports that conclusion.
Report-ready wording:
  * The available memory image is consistent with activity related to memory-only malware, but it does not independently establish motive or user intent.
  * Recovery was limited under the examined conditions; additional corroboration would be required before concluding deliberate destruction.
  * The finding should be read with the collection scope, time-source limits, and alternate explanations described in this report.

===== Confidence and Reliability =====
^ Confidence level ^ What it looks like for this topic ^ How to report it ^
| Low | Memory image exists, but collection scope, time source, or surrounding context is limited. | State the observation and keep interpretation narrow. |
| Moderate | Memory image aligns with Process and module lists, but attribution or intent remains unresolved. | Say the artifacts support the finding, not that they prove it. |
| High | Multiple independent sources agree on sequence, source system, account context, and collection conditions. | Use stronger language, but still separate observed facts from inference. |

===== Related Concepts =====
  * [[wiki:digital_forensics:memory_malware_ir:dynamic_malware_analysis|Dynamic Malware Analysis]] - Often appears nearby in reviews of the same system or behavior.
  * [[wiki:digital_forensics:memory_malware_ir:encryption_keys_in_memory|Encryption Keys in Memory]] - Helps keep the finding grounded in a wider evidence pattern.
  * [[wiki:digital_forensics:memory_malware_ir:fileless_malware|Fileless Malware]] - Useful when checking whether another artifact supports the same interpretation.
  * [[wiki:digital_forensics:memory_malware_ir:malware_triage|Malware Triage]] - Often appears nearby in reviews of the same system or behavior.
  * [[wiki:digital_forensics:memory_malware_ir:memory_acquisition|Memory Acquisition]] - Helps keep the finding grounded in a wider evidence pattern.
  * [[wiki:digital_forensics:memory_malware_ir:memory_images|Memory Images]] - Often appears nearby in reviews of the same system or behavior.

===== Tools =====
  * [[https://remnux.org/|REMnux]] - Linux malware analysis environment.
  * [[https://github.com/mandiant/flare-vm|FLARE-VM]] - Windows malware analysis toolkit.
  * [[https://ghidra-sre.org/|Ghidra]] - Reverse engineering suite.
  * [[https://virustotal.github.io/yara/|YARA]] - Pattern matching for malware triage.
  * [[https://github.com/mandiant/capa|capa]] - Capability detection for executable analysis.
  * [[https://github.com/mandiant/flare-floss|FLOSS]] - String decoding and extraction for malware analysis.
  * [[https://github.com/volatilityfoundation/volatility3|Volatility 3]] - Memory analysis and plugin-driven investigation.
  * [[https://github.com/Velocidex/WinPmem|WinPmem]] - Windows memory acquisition.
  * [[https://github.com/504ensicsLabs/LiME|LiME]] - Linux memory acquisition.
  * [[https://github.com/microsoft/avml|AVML]] - Linux memory acquisition for cloud and endpoint response.
  * [[wiki:tools:start|Forensic Tools]] - Full tool directory for the wiki.

===== Limitations of Tools =====
Tools parse, surface, and organize evidence. They do not create conclusions.
Parser output can be affected by version differences, unsupported formats, corrupted records, timezone handling, partial collection, and storage behavior outside the tool's view.
When a tool produces a strong-looking result, validate it against another tool or source where the stakes justify it. A parser can recover a fragment; it cannot tell you whether the fragment deserves a paragraph in the report.

===== References and Further Reading =====
  * [[https://volatility3.readthedocs.io/|Volatility 3 documentation]] - Memory analysis documentation.
  * [[https://yara.readthedocs.io/|YARA documentation]] - YARA rule documentation.
  * [[https://www.cisa.gov/resources-tools|CISA resources and tools]] - CISA cybersecurity resources and tools.
  * [[https://csrc.nist.gov/publications/detail/sp/800-86/final|NIST SP 800-86]] - Guide to integrating forensic techniques into incident response.
  * [[https://www.nist.gov/itl/ssd/software-quality-group/computer-forensics-tool-testing-program-cftt|NIST CFTT]] - Computer Forensics Tool Testing program.

===== See Also =====
  * [[wiki:digital_forensics:memory_malware_ir:start|Memory Malware Ir]]
  * [[wiki:digital_forensics:memory_malware_ir:dynamic_malware_analysis|Dynamic Malware Analysis]]
  * [[wiki:digital_forensics:memory_malware_ir:encryption_keys_in_memory|Encryption Keys in Memory]]
  * [[wiki:digital_forensics:memory_malware_ir:fileless_malware|Fileless Malware]]
  * [[wiki:digital_forensics:memory_malware_ir:malware_triage|Malware Triage]]
  * [[wiki:digital_forensics:memory_malware_ir:memory_acquisition|Memory Acquisition]]
  * [[wiki:digital_forensics:memory_malware_ir:memory_images|Memory Images]]
  * [[wiki:digital_forensics:memory_malware_ir:network_sockets_in_memory|Network Sockets in Memory]]
  * [[wiki:digital_forensics:memory_malware_ir:packed_malware|Packed Malware]]
  * [[wiki:digital_forensics:memory_malware_ir:registry_hives_in_memory|Registry Hives in Memory]]
  * [[wiki:digital_forensics:memory_malware_ir:static_malware_analysis|Static Malware Analysis]]
  * [[wiki:tools:start|Forensic Tools]]
  * [[wiki:resources:start|Project Resources]]

===== Reader Takeaway =====
Memory-Only Malware is useful when it helps explain what the evidence can support and where the limits begin. Treat memory-only malware as one part of a corroborated record, not a shortcut to intent. A YARA hit is a lead, not a tiny conviction wearing curly braces.

===== Use Notes =====
This article is for defensive education and technical reference. It should not be treated as legal, forensic, investigative, compliance, or operational advice without qualified professional judgment.