Office (OOXML) / .XLSX malware analysis — malicious · 110cc4e0f8af5915

MALICIOUS

Office (OOXML) / .XLSX

1.40 MB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 12.0000

MD5: aca6994564bc74c8c9a3d854054b65fa SHA-1: 789594e49f7d79465274d65c56c63bd552ad8c60 SHA-256: 110cc4e0f8af591585be900b5ebdf893f012ae74024129e5b18768bc7d9e35a4

110 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an Excel document containing an embedded OLE object, specifically identified as an Equation Editor object. Heuristics indicate that this object carries a payload-like Ole10Native stream with an anomalous header and size discrepancy, strongly suggesting exploitation of a vulnerability like CVE-2017-11882. This technique is commonly used to execute arbitrary code, likely leading to the download and execution of a secondary malicious payload.

Heuristics 5

Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR

Embedded OLE object xl/embeddings/oleObject1.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY

Embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is an exploit-shaped Equation/OLE payload container seen in malicious OOXML samples. It is not assigned to a specific CVE unless the MTEF/Equation Native primitive also matches.
Embedded OLE object medium OOXML_OLE_OBJECT

Document contains an embedded OLE object
Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET

Excel workbook contains 1 hidden sheet(s) — hidden sheets are commonly used to conceal macro code, staging data, or intermediate payload construction
Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 10

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`ooxml_oleobject_00.bin` `ad1a5decdfbf79b63d8558fda1d662b3f846fa2812107eff919a6856a074c98b`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/oleObject3.bin	29696 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.46, consistent with packed or encrypted content.
`ooxml_oleobject_00_ole10native_00.bin` `d0e65243df358f9ee7948eadb2c9e55da3344dd9a0ee3fcc11d3188c924dc972`	ole-package	OOXML xl/embeddings/oleObject3.bin Ole10Native stream: Ole10Native	28007 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.61, consistent with packed or encrypted content.
`ooxml_oleobject_01.bin` `3a89ee3d738b0d0c426413c281a7d23ca5287e3b1ae1709641af7d1e1dd82ab9`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/oleObject2.bin	1535488 bytes
`ooxml_oleobject_01_ole10native_00.bin` `f7bfcd2cfafe65360c900b06396fb593106749574e01161bc1df7461e65c0804`	ole-package	OOXML xl/embeddings/oleObject2.bin Ole10Native stream: Ole10Native	1520900 bytes
`ooxml_oleobject_02.bin` `5cbffe4895f6d0903937a7d35afb9b97cacdb81ee6ca38aab51349d97451f341`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/oleObject1.bin	959488 bytes
`ooxml_oleobject_02_ole10native_00.bin` `81d607131338dc7587bf2e2132ac46c59c4d2aa12b686a9c50e9ea6641bc0ed6`	ole-package	OOXML xl/embeddings/oleObject1.bin Ole10Native stream: ole10naTIVE	949435 bytes
`ooxml_oleobject_03.bin` `77e39b23d129be207879f807a728d855d69bdaf0f2bb6378862c894b80443d33`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/Microsoft_Office_Word_Macro-Enabled_Document1.docm	121999 bytes
`emf_00.emf` `072a6a893b25f4848345ae02773b4dd141c43ec598f34f1da6844dabe6ca8a42`	ooxml-emf	OOXML EMF part: xl/media/image2.emf	3042216 bytes
`emf_01.emf` `dd165762e2ea05cd6c095e9e76d39c6edc98cef210be4d0f84b46cc1088c1f7e`	ooxml-emf	OOXML EMF part: xl/media/image3.emf	1127736 bytes
`emf_02.emf` `eb97b4a4d12d2ce3a03daf8e3113b792a3fd077f91933e3d2c71372fdbb7f2c2`	ooxml-emf	OOXML EMF part: xl/media/image4.emf	5376 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.