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

Static analysis result for SHA-256 aaa4fd9e9293bd2f…

MALICIOUS

Office (OOXML) / .XLSM

53.0 KB Created: 2020-02-01 18:28:07 UTC Authoring application: Microsoft Excel 12.0000
MD5: 296bc27cb474319d7d61d57f5d9e2b30 SHA-1: dbe04ec6690b0d86d3e016438b1b769d03a9dd0f SHA-256: aaa4fd9e9293bd2fa88106272016abf262804fd4358a6347c8a1b10e8765f3d9
380 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File Execution T1204.002 Malicious File Execution: Malicious File T1059 Command and Scripting Interpreter T1059.003 Command and Scripting Interpreter: Windows Command Shell T1566 Phishing T1566.001 Phishing: Spearphishing Attachment

The sample is an XLSM file containing VBA macros, specifically an Auto_Open macro, which is a common delivery mechanism. It exploits CVE-2017-11882 through an embedded Equation Editor object. The Equation Editor command stager indicates it attempts to execute a command that likely downloads and runs a second-stage payload, as suggested by the ClamAV detection 'Doc.Dropper.Detected-9977031-0'. No specific malware family was identified, but the dropper functionality is clear.

Heuristics 9

  • 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.
  • 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
  • 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.

FilenameKindSourceSize
macros.bas
80797a03218b9b8f680a340facf6f8453b99eb86c5bc7e209d533d619cf393b6		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 38245 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
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
d467ba245981c15cf2f5c9c5dee56ac44b01840bafdcdd8b987f75e2a85a0d32		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject1.bin 22016 bytes
ooxml_oleobject_00_ole10native_00.bin
41452d9acafa4353ba5d471e5b815ffefdd77e0a5636d22c4ce4af7d595b1848		 ole-package OOXML xl/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 19177 bytes
ooxml_oleobject_01.bin
d5d48b4c730e3fbcabadcd4005104fca0c9e1116c4b4e1a4a357f943d07a5862		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject3.bin 5936 bytes
ooxml_oleobject_02.bin
a160d55d8ea0470dbb1d44d2380eeee06a7eaa4a580049740ef5635c1cfcdc81		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject2.bin 26624 bytes
ooxml_oleobject_02_ole10native_00.bin
2d156f71791b82b0af7f3091f7ad0d78e09865f50d7de0185985d5afb4e02cd3		 ole-package OOXML xl/embeddings/oleObject2.bin Ole10Native stream: Ole10Native 23785 bytes
ooxml_oleobject_03.bin
4b764e33ba48d3287ae792e4431eea9a452fc2cad02f48f631db1282117752f7		 ooxml-ole-object OOXML embedded OLE part: xl/vbaProject.bin 62464 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

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