Office (OOXML) / .XLSX malware analysis — malicious · 4ec97839317834ee

MALICIOUS

Office (OOXML) / .XLSX

45.5 KB Created: 2020-02-01 18:28:07 UTC Authoring application: Microsoft Excel 12.0000

MD5: 9cf3faa42e2276a71f224560da95a5ec SHA-1: 381421226b2f8a13ffa0b899bbc0cc19c2940a5d SHA-256: 4ec97839317834ee9ad500d41b2e1bf2e9fba55bb37f0515af2cf509d288818f

380 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.003 Windows Command Shell T1204.002 Malicious File

The XLSX file contains a VBA macro with an Auto_Open function, which is a common technique for initial execution. The macro utilizes WScript.Shell and CreateObject to execute a Base64-decoded command, specifically downloading and executing a file from the URL http://198.12.66.107/UFSjaPF.exe. This indicates a downloader or stager functionality.

Heuristics 9

Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR

Embedded OLE object xl/embeddings/oleObject3.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
Shell() call in VBA critical OLE_VBA_SHELL

Shell() call in VBA
WScript.Shell usage critical OLE_VBA_WSCRIPT

WScript.Shell usage
VBA Base64-decoded Shell command stager critical OLE_VBA_BASE64_SHELL_COMMAND_STAGER

VBA auto-exec macro decodes Base64 string literals into command or script-launch text and executes the result with Shell. This catches cmd/cscript/PowerShell/VBS launchers hidden from plain keyword matching.

URL http://198.12.66.107/UFSjaPF.exe
Auto_Open macro high OLE_VBA_AUTO

Auto_Open macro
CreateObject call high OLE_VBA_CREATEOBJ

CreateObject call
Suspicious extracted artifact high 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.
VBA project inside OOXML medium OOXML_VBA

Document contains vbaProject.bin — VBA macros present
Embedded OLE object medium OOXML_OLE_OBJECT

Document contains an embedded OLE object

Extracted artifacts 9

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`macros.bas` `47a620ca8dee09f70e16fe92b26c47ba1848d85ac4d2d43e62a10dddff5e8391`	vba-macro	oletools.olevba.extract_macros (decoded VBA source from OOXML)	38973 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 shell/COM execution token(s). Carved artifact contains 1 long base64-like blob(s). Carved macro source contains an auto-exec entry point and execution/download terms.
`ooxml_oleobject_00.bin` `ca62fa9ff0d251ea52367194b508fb5029d2834a4d48e760feaae762e752d014`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/oleObject3.bin	5936 bytes
`ooxml_oleobject_01.bin` `49f668e4d7ce440cbbe3b646a9458678b74aa114cc0ea55bcf3bb2d16a06f9d5`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/oleObject1.bin	3584 bytes
`ooxml_oleobject_01_ole10native_00.bin` `0ee490e623853b59cac34be1ac1fe82a1ec74de7ac324520fa11864ae314e909`	ole-package	OOXML xl/embeddings/oleObject1.bin Ole10Native stream: Ole10Native	982 bytes
`ooxml_oleobject_02.bin` `c40762df9897f73c8c2abe1dde6fd953da9e678922e18770736a55ab997b688d`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/oleObject2.bin	9216 bytes
`ooxml_oleobject_02_ole10native_00.bin` `c82418918a537de408571b9d9fba40ce3d54440a55bc93339c9684767c19a8b4`	ole-package	OOXML xl/embeddings/oleObject2.bin Ole10Native stream: Ole10Native	6397 bytes
`ooxml_oleobject_03.bin` `c817b1f071709a5037e895ee47d10f6f1b89d2b5c3fcfefb09d7f3cc478fd702`	ooxml-ole-object	OOXML embedded OLE part: xl/vbaProject.bin	64000 bytes
`emf_00.emf` `979dde2aed02f077c16ae53546c6df9eed40e8386d6db6fc36aee9f966d2cb82`	ooxml-emf	OOXML EMF part: xl/media/image1.emf	4968 bytes
`emf_01.emf` `4d4d1e7b04c99dcb8e885915068ad6f74cc2333e91580cdae5ccaa00c427247f`	ooxml-emf	OOXML EMF part: xl/media/image2.emf	1536 bytes

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