Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 bb5bf7ba61901e39…

MALICIOUS

Office (OLE) / .XLS

775.5 KB Created: 2020-06-22 10:41:03 Authoring application: Microsoft Excel
MD5: 10c5f13895dc723a2d5e2bfbed156b77 SHA-1: d7e54874df9f40c3cf8f8a4ba3da7ac28cddf57f SHA-256: bb5bf7ba61901e393ff754cd5bc478a3d596a4e5a72dc6f8f35b29a19342ff9c
520 Risk Score

Malware Insights

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

The sample is an Excel spreadsheet containing VBA macros. The Workbook_Open macro is configured to execute a shell command, which likely downloads and executes a secondary payload. A PE executable was found embedded within the document, further indicating a dropper or downloader functionality. The presence of VirtualAlloc, LoadLibrary, and GetProcAddress API calls suggests the execution of malicious code.

Heuristics 13

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Embedded PE executable critical OLE_EMBEDDED_EXE
    MZ/PE header found inside document — possible embedded executable
  • ClamAV: Win.Dropper.Hideproc-6663113-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Dropper.Hideproc-6663113-0
  • 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.
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Reference to LoadLibrary API high SC_STR_LOADLIBRARY
    Reference to LoadLibrary API
  • Reference to GetProcAddress API high SC_STR_GETPROCADDRESS
    Reference to GetProcAddress API
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • 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.
  • 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.
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3.org/2000/svg
    • http://www.w3.org/1999/xlink

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
fcff4f50ea14c1d8fabc0a22abb3e21488e64d68180902c6335ac52d63d04d20
vba-macro oletools.olevba.extract_macros (decoded VBA source) 10578 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
embedded_office_00006265.exe
27195337ee6dd1647af81a19fac2eeae9f284b5171b779c69c7c3fe63e67885f
embedded-pe Office MZ+PE at offset 0x6265 768923 bytes
Detection
ClamAV: Win.Dropper.Hideproc-6663113-0
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
ole10native_00.bin
6a7ddfbd62d7b14acf0191ff71596164ed9e322382a63f3f68d56cb2c2a68d56
ole-package OLE Ole10Native stream: MBD00AAB60E/Ole10Native 612007 bytes