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

Static analysis result for SHA-256 fc2c7c6f30ea17c4…

MALICIOUS

Office (OLE) / .XLSX

227.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 9cab7cd817d7e40c017508d72919a6af SHA-1: 2093eb22cbcc280af937cf1b86f26dbe37ff5b3e SHA-256: fc2c7c6f30ea17c4fb186e5ef2ad8d32c2019523bcf12502ef9c5e9fadee6c86
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The sample is an Excel 4.0 macro-enabled workbook. It contains an Auto_Open macro that uses dangerous functions and includes environment evasion checks. The document body text prompts the user to 'Enable Editing' and 'Enable Content', indicating a social engineering lure to execute the macro. The macro is likely designed to download and execute a second-stage payload.

Heuristics 4

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • XLM Auto_Open environment-evasion HALT gate high OLE_XLM_ENVIRONMENT_EVASION_HALT
    Excel 4.0 macro sheet auto-executes multiple GET.WORKSPACE / GET.WINDOW environment checks and halts execution when the host does not match the expected user environment. This is a common sandbox-evasion pattern in XLM malware and is stronger than a bare XLM macro-sheet indicator.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
c775227b4c49a760a512a0c56c1af60c5efb45b7e8364ec3077cab2877fd75b9
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 325665 bytes