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

Static analysis result for SHA-256 d7c99409cf5dfb96…

MALICIOUS

Office (OOXML) / .XLSX

45.4 KB Created: 2020-02-01 18:28:07 UTC Authoring application: Microsoft Excel 12.0000
MD5: a7822b9ccd2ef0f3cf71769d22491aaf SHA-1: 0dc7f898456f663f10150f21bda9760937e67318 SHA-256: d7c99409cf5dfb9644cf3672c5ae1d9fa028f7b9412dbb15ad4abd542c47b025
380 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1105 Ingress Tool Transfer T1204.002 Malicious File

The file contains VBA macros, including an Auto_Open macro, which is designed to execute automatically. The macros utilize WScript.Shell and CreateObject to call the Shell() function, which is used to download and execute a second-stage payload from the URL http://198.12.66.107/EPwplzp.exe. This indicates a downloader or droppper 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/EPwplzp.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.

FilenameKindSourceSize
macros.bas
f79a99c67b59b43b0815958b4dad190db37e396dbf313dd8a7f2bd876d1f335a
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 38961 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
aa90ad5f1b522fbf69b4bd5f1e36d636899a46ea13f999818339e837fe0bac15
ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject2.bin 9216 bytes
ooxml_oleobject_00_ole10native_00.bin
498a59cefd432bd29176ac1f43731c0dbd6b4f58464d06e8d7f985611de899ae
ole-package OOXML xl/embeddings/oleObject2.bin Ole10Native stream: Ole10Native 6385 bytes
ooxml_oleobject_01.bin
ca62fa9ff0d251ea52367194b508fb5029d2834a4d48e760feaae762e752d014
ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject3.bin 5936 bytes
ooxml_oleobject_02.bin
49f668e4d7ce440cbbe3b646a9458678b74aa114cc0ea55bcf3bb2d16a06f9d5
ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject1.bin 3584 bytes
ooxml_oleobject_02_ole10native_00.bin
0ee490e623853b59cac34be1ac1fe82a1ec74de7ac324520fa11864ae314e909
ole-package OOXML xl/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 982 bytes
ooxml_oleobject_03.bin
aa33789b0c6dd7b3088ba0b1bde45c9adf8ccbff95d33a918b0772eaca3f5ca0
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