Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6da1b58e3b3a4301…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:45:29 Authoring application: Microsoft Excel First seen: 2021-10-04
MD5: 8638eed88d09fc9dd59ba9076159af69 SHA-1: 704d2415338db114d6255d52eb3075d6a166a92b SHA-256: 6da1b58e3b3a43018aad580d03ba4b53930a7953f4eda7b8ef50ab9e6bfcf0d9
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 entry, which is a common technique for executing malicious code upon opening the document. The 'XLM Auto_Open with dangerous formula APIs' firing, specifically mentioning 'RUN=0', suggests the macro attempts to run an external program. While no specific URLs or hashes were extracted, the presence of Auto_Open and dangerous functions strongly implies 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) 6635 bytes
SHA-256: 357bf9cca574ba54ee0d4c513937ad06454ef6825da84d4bc2757564c0adec96
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  RDOiaWyHxzM
' 0018     25 LABEL : Cell Value, String Constant - agmwWWtJdR len=0 
' 0018     23 LABEL : Cell Value, String Constant - aibmtDRA len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G155 
' 0018     20 LABEL : Cell Value, String Constant - CDUUN len=0 
' 0018     25 LABEL : Cell Value, String Constant - CnklUPmKgb len=0 
' 0018     23 LABEL : Cell Value, String Constant - ehIoHLMs len=0 
' 0018     22 LABEL : Cell Value, String Constant - fDEGMFK len=0 
' 0018     26 LABEL : Cell Value, String Constant - fvhYloEjZOz len=0 
' 0018     24 LABEL : Cell Value, String Constant - GvFaTBmnL len=0 
' 0018     24 LABEL : Cell Value, String Constant - gzUMdEUXp len=0 
' 0018     24 LABEL : Cell Value, String Constant - HYTbJeaOs len=0 
' 0018     27 LABEL : Cell Value, String Constant - IVgtpZgEqAGU len=0 
' 0018     21 LABEL : Cell Value, String Constant - KjqPgJ len=0 
' 0018     24 LABEL : Cell Value, String Constant - LoriMwItv len=0 
' 0018     20 LABEL : Cell Value, String Constant - milds len=0 
' 0018     23 LABEL : Cell Value, String Constant - siBeHCNM len=0 
' 0018     22 LABEL : Cell Value, String Constant - uOSSSAE len=0 
' 0018     21 LABEL : Cell Value, String Constant - vapQby len=0 
' 0018     23 LABEL : Cell Value, String Constant - vgUgtQDP len=0 
' 0018     27 LABEL : Cell Value, String Constant - vuGVYJQwaesd len=0 
' 0018     24 LABEL : Cell Value, String Constant - XdCalNdVq 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 
... (truncated)

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