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

Static analysis result for SHA-256 16e061f7bac8e96b…

MALICIOUS

Office (OLE) / .XLS

90.5 KB Created: 2020-11-26 06:44:58 Authoring application: Microsoft Excel
MD5: f0578e01735dd9cdafa0cc2fd17ef825 SHA-1: 521bac484265f0712f7f0b55b1d42cfd06f428a4 SHA-256: 16e061f7bac8e96b6df00c7ce3547ba5814d8d5c84f325393f59965f3f39cc3d
502 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1105 Ingress Tool Transfer T1082 System Information Discovery

The sample is an Excel file containing obfuscated VBA macros. The Workbook_Open macro is designed to execute automatically, leveraging WScript.Shell to download and execute a second-stage payload. The document body contains a lure to enable content, which is a common tactic for macro-based malware.

Heuristics 12

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • ClamAV: Xls.Macro.Obfuscation-9804250-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Macro.Obfuscation-9804250-0
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_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 macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
1e22dccf4f2d7ab3e7f0ef14a0187eed788e8101303fb86e5e75ddb1899bbfab
vba-macro oletools.olevba.extract_macros (decoded VBA source) 36690 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 113 long base64-like blob(s).