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

Static analysis result for SHA-256 0bd126bf42022279…

MALICIOUS

Office (OOXML) / .XLSM

52.8 KB Created: 2020-02-01 18:28:07 UTC Authoring application: Microsoft Excel 12.0000
MD5: 8de209c2267a4bbd45e4359b951e9b4f SHA-1: 361c0dd0cafbe97d329577b970ab8aca8f6917e0 SHA-256: 0bd126bf42022279566f892b5f0df9f4ea976fce2389e188dc7dbfddef6f5de5
442 Risk Score

Malware Insights

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

The critical heuristic 'CVE_2017_11882_EQUATION_NATIVE_CMD' indicates the exploitation of CVE-2017-11882 through an embedded Equation Editor object. The embedded VBA macro, specifically the Auto_Open subroutine, uses CreateObject to execute a command that downloads and runs a script from a temporary file. This is further supported by the ClamAV detection signatures indicating 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
df9b659f8fbb34eb1a41266c793267c090fce4ebc4a84c3a3c5c7e9bab238fef
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 37181 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
ooxml_oleobject_00.bin
126a6f3e0ae873e3ad10de228d1c8d3ac7ff5a91cbb09a119ac6a615bdca9ca1
ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject1.bin 22016 bytes
ooxml_oleobject_00_ole10native_00.bin
26dc75f6c6642e65377e24f9fdcf467792af7d9bea1106c451068a0e21499419
ole-package OOXML xl/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 19177 bytes
ooxml_oleobject_01.bin
bdd8b1b89f2948a4007ad2a605a1d96b21eee52c56460d11fdba0ddaae9d9197
ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject2.bin 26112 bytes
ooxml_oleobject_01_ole10native_00.bin
2d01def54c0a7f95b29baacf04857fe12fa67e7bdfd9bf600804dc71b548812f
ole-package OOXML xl/embeddings/oleObject2.bin Ole10Native stream: Ole10Native 23467 bytes
ooxml_oleobject_02.bin
a3531ab05f38ba678a5af642b1e8f0d7b96821d5683e1fc12dc6e7d2b181ee95
ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject3.bin 5936 bytes
ooxml_oleobject_03.bin
77db020be1eadedd70fa679600aabf07e602e042f8cb31bbbcf0ed06d902df06
ooxml-ole-object OOXML embedded OLE part: xl/vbaProject.bin 60416 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