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

Static analysis result for SHA-256 263a86febda2b83b…

MALICIOUS

Office (OOXML) / .XLSX

47.5 KB Created: 2020-02-01 18:28:07 UTC Authoring application: Microsoft Excel 12.0000
MD5: e5d4386354ade3999527f0fd5e4449d8 SHA-1: a37c379a989d83ff23b04cfc8cdba175e081fb84 SHA-256: 263a86febda2b83b36e0f7cd950be009b6732e9793cab33152ab0542b4707136
500 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The file is an Excel macro-enabled document containing an Auto_Open macro that utilizes WScript.Shell to execute a Base64-decoded command. This command is identified as a URL pointing to an executable file, indicating the macro's purpose is to download and run a second-stage payload. The presence of an Equation Editor OLE object and ClamAV detections further support its malicious nature as a dropper.

Heuristics 11

  • 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/DVmq0lawgaD0Zmv.exe
  • ClamAV: Xls.Dropper.Agent-7678013-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-7678013-0
  • 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
c3050cd6fcd374c1d65ce6d29f749d647694ce542096fa098d1dc7d383a94799		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 44919 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
ad42f9bcec245333b066b8e87c61bb3de70ad9ab48c06903fa4454956115c514		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject1.bin 3584 bytes
ooxml_oleobject_00_ole10native_00.bin
b3873bb2e38f71b3e635388edfb18d16a315d650487fd6a1fa0f478fa060bac0		 ole-package OOXML xl/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 1002 bytes
ooxml_oleobject_01.bin
ed53cfba4460275d62d43305be97f319b562bda73b2177bdf53c4429219b5393		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject3.bin 5936 bytes
ooxml_oleobject_02.bin
8eacbda7f5e92e854a28e066ed43566929c328d021d3040ac31c4737f6df9120		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject2.bin 9216 bytes
ooxml_oleobject_02_ole10native_00.bin
c369fa206f0e3f31f492e9a77e86c1429c12475992808cd1c8c7bf9aaa0c15cd		 ole-package OOXML xl/embeddings/oleObject2.bin Ole10Native stream: Ole10Native 6403 bytes
ooxml_oleobject_03.bin
14d1e08e500aa8b2acfe59b767470d086296a28de89b413f89f321214e3efb04		 ooxml-ole-object OOXML embedded OLE part: xl/vbaProject.bin 72704 bytes
Detection
ClamAV: Xls.Dropper.Agent-7678013-0
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.