Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b4d9d3b09c4d0fe7…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:42:12 Authoring application: Microsoft Excel First seen: 2021-09-18
MD5: 7b34d9f6d524373ab9d5f999cf7cb499 SHA-1: 5f486252fe4d7b554ef0ef93e2b990fa89f03762 SHA-256: b4d9d3b09c4d0fe7b84295350680d7f1d4c9121af65f7ebf00ade31882c37334
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 containing an Auto_Open function, which is a common technique for executing malicious code upon opening. The presence of dangerous formula APIs like RUN indicates an intent to execute arbitrary commands or download further payloads. No specific family could be identified, but the technique is indicative of a downloader or initial execution stage.

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) 6549 bytes
SHA-256: bbb2f61668912e4d4055ab138c629a3c2fc756fea83235f055a72c58b77bc2fb
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  TujoYNX
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D161 
' 0018     24 LABEL : Cell Value, String Constant - bMwkfzXct len=0 
' 0018     23 LABEL : Cell Value, String Constant - bYVnfbfK len=0 
' 0018     24 LABEL : Cell Value, String Constant - ciDFtmsPY len=0 
' 0018     21 LABEL : Cell Value, String Constant - eDozYe len=0 
' 0018     22 LABEL : Cell Value, String Constant - fcCphSW len=0 
' 0018     20 LABEL : Cell Value, String Constant - gEjzO len=0 
' 0018     22 LABEL : Cell Value, String Constant - HcxiHwX len=0 
' 0018     26 LABEL : Cell Value, String Constant - jBDewRkofxY len=0 
' 0018     27 LABEL : Cell Value, String Constant - jpJuPYebAKPM len=0 
' 0018     21 LABEL : Cell Value, String Constant - KGlqyA len=0 
' 0018     23 LABEL : Cell Value, String Constant - MFWZfnfD len=0 
' 0018     26 LABEL : Cell Value, String Constant - mydcBSYSNWY len=0 
' 0018     25 LABEL : Cell Value, String Constant - nQFopKExBF len=0 
' 0018     27 LABEL : Cell Value, String Constant - QfzqUaDpIiOd len=0 
' 0018     23 LABEL : Cell Value, String Constant - qVdfDCZo len=0 
' 0018     26 LABEL : Cell Value, String Constant - sYmUhpzQQKT len=0 
' 0018     20 LABEL : Cell Value, String Constant - VyTvU len=0 
' 0018     23 LABEL : Cell Value, String Constant - xuiPPOlR len=0 
' 0018     23 LABEL : Cell Value, String Constant - yMajjKRA len=0 
' 0018     20 LABEL : Cell Value, String Constant - YPfmF 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
... (truncated)

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