Malicious Office (OOXML) / .XLSM — malware analysis report

Static analysis result for SHA-256 0a74e76992fb20a3…

MALICIOUS

Office (OOXML) / .XLSM

51.9 KB Created: 2020-02-01 18:28:07 UTC Authoring application: Microsoft Excel 12.0000
MD5: 80d75ff578a097216a8d68447b263b43 SHA-1: f2c86a031eae57656d4da268aa00ffb08dfb9f08 SHA-256: 0a74e76992fb20a3871245a26d14036f131eda3b0339db98b2ceecce5fbd90c0
442 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Visual Basic

The sample is an XLSM file containing VBA macros, including an Auto_Open macro that utilizes CreateObject. It specifically leverages the CVE-2017-11882 vulnerability within the Equation Editor OLE object to execute a command. This command, 'cmd /K rEN %temp%\qv&wSCRIpT %tmp%\v..wsf', is designed to download and execute a second-stage payload, indicated by the ClamAV detection as a dropper.

Heuristics 11

  • CVE-2017-11882 — Equation Editor command stager critical CVE likely CVE_2017_11882_EQUATION_NATIVE_CMD
    Embedded Equation Editor OLE data contains an invalid Equation Native/MTEF stream with an embedded command stager. This is likely CVE-2017-11882 exploitation because the vulnerable Equation Editor component is reached and the malformed native stream directly carries process-launch bytes.
  • 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.
  • Embedded Office object carries macros critical OFFICE_EMBEDDED_MACRO_OBJECT
    This document embeds a second Office file that itself contains a VBA macro project or an Excel 4.0 (XLM) macro sheet. Hiding a macro-bearing workbook or document inside another document — frequently under an obfuscated, non-standard part name — is a macro-smuggling technique that defeats scanners which only inspect the outer document's macro storage. No benign authoring workflow stages a hidden macro project this way.
  • ClamAV: Doc.Dropper.Detected-9977031-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Detected-9977031-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object
  • 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 9

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
4b4cd22ec01a4c0b88f8bae558356d6546b74100ad954fd774d3c199ef9dc88c		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 26190 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
ooxml_oleobject_00.bin
d9450703b3b6fa8de3cfd14d850adbca0a57bb57d8338e44d641f9899f3d5a32		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject2.bin 15360 bytes
ooxml_oleobject_00_ole10native_00.bin
c78a37ba02540f8f954c2107720cb16f947ce90c6a81d66630db191ca4df41e3		 ole-package OOXML xl/embeddings/oleObject2.bin Ole10Native stream: Ole10Native 12746 bytes
ooxml_oleobject_01.bin
fbe7431a384a71c9cc2d85f7b0354ef3a0e78256990a0820d18689342e319e7d		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject3.bin 5936 bytes
ooxml_oleobject_02.bin
539b41dd40f4f01df98eaace622bf2dbc65532802757fb03839a0a5d02880bdf		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject1.bin 13312 bytes
ooxml_oleobject_02_ole10native_00.bin
67c307c8314fb9f68f74b27f781bd27754306d46f40c60a31cc2e4b68e3b93eb		 ole-package OOXML xl/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 10438 bytes
ooxml_oleobject_03.bin
f342ebb0c6e3e26eaac80e837ad052b75ecf74cad3a6d558d0d4b5ccc6a70916		 ooxml-ole-object OOXML embedded OLE part: xl/vbaProject.bin 51712 bytes
Detection
ClamAV: Doc.Dropper.Detected-9977031-0
Obfuscation or payload: unlikely
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

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