Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 226a39db31fccd3a…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:44:00 Authoring application: Microsoft Excel First seen: 2021-09-18
MD5: 522334f4f459f0e23f9489d571c41713 SHA-1: c8a2e7af2c15e978bbdae8ac6edec7630e234180 SHA-256: 226a39db31fccd3a61de4cc895d2fbc77207c0c4cffac6ab79e6adbf8e3993d4
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel 4.0 macro-enabled workbook. Static analysis detected an Auto_Open defined name, which is a critical indicator of malicious intent as it allows for automatic execution of code upon opening the workbook. The presence of dangerous formula APIs further supports this. The macro sheet likely contains code to download and execute a secondary payload, a common technique for initial access.

Heuristics 3

  • 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.
  • 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 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6615 bytes
SHA-256: f5e14207ba97ceec29f6889ab63c28a29d498458508b6e51070359d01870e370
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  EsKbGswo
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H177 
' 0018     26 LABEL : Cell Value, String Constant - bPJyPzyeNqW len=0 
' 0018     26 LABEL : Cell Value, String Constant - dJAyoXaiXcO len=0 
' 0018     26 LABEL : Cell Value, String Constant - dzNdQUTlNod len=0 
' 0018     22 LABEL : Cell Value, String Constant - EMNLfUu len=0 
' 0018     21 LABEL : Cell Value, String Constant - FIDppR len=0 
' 0018     26 LABEL : Cell Value, String Constant - fQPvLJzzWXw len=0 
' 0018     21 LABEL : Cell Value, String Constant - GEcbOS len=0 
' 0018     24 LABEL : Cell Value, String Constant - IgviGawje len=0 
' 0018     24 LABEL : Cell Value, String Constant - IxGlxTQUD len=0 
' 0018     22 LABEL : Cell Value, String Constant - JwLOPZE len=0 
' 0018     25 LABEL : Cell Value, String Constant - MPSCIyskFU len=0 
' 0018     26 LABEL : Cell Value, String Constant - nOETWgnMfhB len=0 
' 0018     21 LABEL : Cell Value, String Constant - oQUYmp len=0 
' 0018     22 LABEL : Cell Value, String Constant - poFJnyp len=0 
' 0018     20 LABEL : Cell Value, String Constant - qrmTM len=0 
' 0018     24 LABEL : Cell Value, String Constant - RGbnDESDc len=0 
' 0018     21 LABEL : Cell Value, String Constant - rObeNA len=0 
' 0018     26 LABEL : Cell Value, String Constant - tazcpJFMqoj len=0 
' 0018     24 LABEL : Cell Value, String Constant - XcAQACNgA len=0 
' 0018     27 LABEL : Cell Value, String Constant - ylxWlAhwVPym len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00
... (truncated)

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