Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b0f3a91434ef597e…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:44:06 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: 78c941a0f4728d84eadf0bf72e945ec3 SHA-1: 434d115284f1b9dab92278afccc771f7ca0cccc9 SHA-256: b0f3a91434ef597ee76637a0cc8e6c45c84dfb23e723ff9082ce7ec86214263e
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding indicating potential malicious execution. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary commands. While no specific URLs or hashes were extracted, the Auto_Open macro is highly indicative of a downloader or initial execution stage for further malicious activity.

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) 6524 bytes
SHA-256: 3f02f21cca9d9202dccd3839f415918d78f34ebe0d66f6347c94286bd5019605
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 -  flMoVDGf
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E174 
' 0018     21 LABEL : Cell Value, String Constant - bizVNh len=0 
' 0018     22 LABEL : Cell Value, String Constant - CSaOixS len=0 
' 0018     20 LABEL : Cell Value, String Constant - FNPeA len=0 
' 0018     25 LABEL : Cell Value, String Constant - gFSoDkaWzp len=0 
' 0018     20 LABEL : Cell Value, String Constant - IjcFr len=0 
' 0018     27 LABEL : Cell Value, String Constant - JtbjFACYUeeH len=0 
' 0018     22 LABEL : Cell Value, String Constant - KMTAdQM len=0 
' 0018     21 LABEL : Cell Value, String Constant - LlySbK len=0 
' 0018     26 LABEL : Cell Value, String Constant - LVCiGCJxcFe len=0 
' 0018     24 LABEL : Cell Value, String Constant - nKgFHdevv len=0 
' 0018     23 LABEL : Cell Value, String Constant - nRRBzbUh len=0 
' 0018     23 LABEL : Cell Value, String Constant - QhIfxJZD len=0 
' 0018     24 LABEL : Cell Value, String Constant - RdoNeSVcN len=0 
' 0018     23 LABEL : Cell Value, String Constant - temgPvxc len=0 
' 0018     27 LABEL : Cell Value, String Constant - txhTDjsseQHc len=0 
' 0018     27 LABEL : Cell Value, String Constant - UjPFxiQYXjyO len=0 
' 0018     24 LABEL : Cell Value, String Constant - wmgdaDsxK len=0 
' 0018     25 LABEL : Cell Value, String Constant - YtCmitRJiF len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZDTIPWI len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZEVsYRC 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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