Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e4f61218c829bb6b…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:46:54 Authoring application: Microsoft Excel First seen: 2021-09-15
MD5: cd5631723d1c2c4e64f84e3fce946842 SHA-1: 8ceeb91b1357780f2efd4f94e9d139e77fb3806f SHA-256: e4f61218c829bb6ba59c36e54c3d69cc30f5bea66dcc1f113eaea18ca3d1a9dc
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open defined name, which is a common technique for executing malicious code upon opening the document. The macro sheet contains a reference to 'Auto_Open', suggesting it will automatically run when the workbook is opened. The presence of dangerous formula APIs further supports malicious intent. The macro likely downloads and executes a second-stage payload, although the specific payload and its destination are not detailed in the provided evidence.

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) 6517 bytes
SHA-256: 46a5285ba3adb4bbbe4dcd4ab4768fff3e4ad9b426bfc43dba7ca002cd8c3701
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  MjZRPS
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F180 
' 0018     27 LABEL : Cell Value, String Constant - bEcCdzergxWv len=0 
' 0018     20 LABEL : Cell Value, String Constant - bHjRm len=0 
' 0018     22 LABEL : Cell Value, String Constant - cddtNXq len=0 
' 0018     21 LABEL : Cell Value, String Constant - cuBoSc len=0 
' 0018     21 LABEL : Cell Value, String Constant - HHZaQH len=0 
' 0018     25 LABEL : Cell Value, String Constant - htTrgDzwzc len=0 
' 0018     21 LABEL : Cell Value, String Constant - LcOFpf len=0 
' 0018     23 LABEL : Cell Value, String Constant - leetXEIM len=0 
' 0018     24 LABEL : Cell Value, String Constant - lMRGmrXNx len=0 
' 0018     25 LABEL : Cell Value, String Constant - lPcbkGiWZi len=0 
' 0018     27 LABEL : Cell Value, String Constant - MXCFTCqvDtgU len=0 
' 0018     25 LABEL : Cell Value, String Constant - PudUEywsrh len=0 
' 0018     21 LABEL : Cell Value, String Constant - qDsalA len=0 
' 0018     23 LABEL : Cell Value, String Constant - RElNLzVD len=0 
' 0018     20 LABEL : Cell Value, String Constant - SYgNb len=0 
' 0018     24 LABEL : Cell Value, String Constant - taZEKPnmm len=0 
' 0018     24 LABEL : Cell Value, String Constant - tCqDYTeZl len=0 
' 0018     24 LABEL : Cell Value, String Constant - vgDkhKFek len=0 
' 0018     20 LABEL : Cell Value, String Constant - VXYMs len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZzJAnDayA 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
' 00fd     10 LABEL
... (truncated)

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