Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1aac7f15bef5b9c9…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:54 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: 51c9db8055e86a3db2dbfd220fb6f5b2 SHA-1: f7901ad890da119ce998f115bd7e6ddc3ef0b088 SHA-256: 1aac7f15bef5b9c97fcff89dae8618a898dfcdcc2c8634d076714cb1f607692e
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 method for executing malicious code upon opening the document. The macro sheet contains references to dangerous formula APIs, specifically 'RUN', suggesting it is designed to execute external commands or download payloads. No specific URLs or hashes were extracted, but the technique 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) 6516 bytes
SHA-256: 417fd9b980adaf999d27179b67f941959038d553307b5d1dcbd9c0ca4594c1b8
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  WNaP
' 0018     25 LABEL : Cell Value, String Constant - AUsAiCdZmE len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F157 
' 0018     22 LABEL : Cell Value, String Constant - FHJusvd len=0 
' 0018     23 LABEL : Cell Value, String Constant - gWuzDrNs len=0 
' 0018     21 LABEL : Cell Value, String Constant - hvRkOL len=0 
' 0018     21 LABEL : Cell Value, String Constant - IbDsGa len=0 
' 0018     23 LABEL : Cell Value, String Constant - jBaVSXMG len=0 
' 0018     24 LABEL : Cell Value, String Constant - mfwZhgfHk len=0 
' 0018     25 LABEL : Cell Value, String Constant - mppqIsNAXs len=0 
' 0018     27 LABEL : Cell Value, String Constant - pbcqkcHcEPdm len=0 
' 0018     27 LABEL : Cell Value, String Constant - QrAWQDsTWBjK len=0 
' 0018     26 LABEL : Cell Value, String Constant - RfdrrCPvoTy len=0 
' 0018     23 LABEL : Cell Value, String Constant - sfMUiMKI len=0 
' 0018     24 LABEL : Cell Value, String Constant - sIdRRYinH len=0 
' 0018     26 LABEL : Cell Value, String Constant - TeLnruzkwOz len=0 
' 0018     25 LABEL : Cell Value, String Constant - UjFbJyhAhD len=0 
' 0018     26 LABEL : Cell Value, String Constant - uLqPjFHRNNN len=0 
' 0018     26 LABEL : Cell Value, String Constant - veqWDmysXOP len=0 
' 0018     22 LABEL : Cell Value, String Constant - VzVJzvG len=0 
' 0018     23 LABEL : Cell Value, String Constant - xLTpdUrl len=0 
' 0018     25 LABEL : Cell Value, String Constant - XsTifRVwda 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/ SS
... (truncated)

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