Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 78b3383e8de0046b…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:38:01 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: fa2a37286cb2f9b7aada0ec426412606 SHA-1: 1cd07ca061b610d6b6ff9c2a9069d6f0dacba042 SHA-256: 78b3383e8de0046bfa82af3a322655000b25fadf307430367194c13b7eb9bcae
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a known technique for executing malicious code upon opening the workbook. The critical heuristic firings indicate the presence of dangerous formula APIs within the Auto_Open macro, suggesting it's designed to run arbitrary commands. No specific family could be identified, and no external IOCs were extracted.

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) 6552 bytes
SHA-256: 56ba83be3d74fed84b8772d054c67ad7f93d212bc40f406fdb07d213b2a76a11
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 -  YrOwpE
' 0018     27 LABEL : Cell Value, String Constant - aFTMfxGDpmFC len=0 
' 0018     27 LABEL : Cell Value, String Constant - aghrmmAnWOMW len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H142 
' 0018     21 LABEL : Cell Value, String Constant - DOOkoD len=0 
' 0018     20 LABEL : Cell Value, String Constant - GRAkC len=0 
' 0018     20 LABEL : Cell Value, String Constant - HrdQi len=0 
' 0018     20 LABEL : Cell Value, String Constant - idxOC len=0 
' 0018     27 LABEL : Cell Value, String Constant - INZDTCpfArxo len=0 
' 0018     25 LABEL : Cell Value, String Constant - JlzMgOvyCk len=0 
' 0018     21 LABEL : Cell Value, String Constant - KWKWZm len=0 
' 0018     23 LABEL : Cell Value, String Constant - oFJaNowx len=0 
' 0018     24 LABEL : Cell Value, String Constant - OwVejVkSt len=0 
' 0018     20 LABEL : Cell Value, String Constant - qlVGs len=0 
' 0018     27 LABEL : Cell Value, String Constant - QplUOHhQRreb len=0 
' 0018     27 LABEL : Cell Value, String Constant - RAdXnlgYrCpM len=0 
' 0018     23 LABEL : Cell Value, String Constant - RvgeoTkn len=0 
' 0018     24 LABEL : Cell Value, String Constant - SinHVexHq len=0 
' 0018     22 LABEL : Cell Value, String Constant - SVLWCXu len=0 
' 0018     20 LABEL : Cell Value, String Constant - TjnRg len=0 
' 0018     20 LABEL : Cell Value, String Constant - upIwC len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZipselSCNWpu 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 L
... (truncated)

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