Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1da659b6bcdd1d7f…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:45:08 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: 495776422d8e1cb3ec1b93a345ea8e54 SHA-1: b38ee3f44f370de7be42dab262d78202b2b7f782 SHA-256: 1da659b6bcdd1d7ffbcc89830f7e60e1be9d63d239658bf4f181b2e26cb8cdbb
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 automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code, likely downloading and running a second-stage payload. The macro sheet itself is heavily obfuscated, preventing a more detailed analysis of its specific actions.

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) 6641 bytes
SHA-256: 93d2977d011494db3b82dc06dd73bd5746f9817d561e2fc884d7f6487e4da2dc
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 -  SsLb
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C170 
' 0018     24 LABEL : Cell Value, String Constant - AvasIjMth len=0 
' 0018     20 LABEL : Cell Value, String Constant - dKiDl len=0 
' 0018     27 LABEL : Cell Value, String Constant - fWgsVvCIssoF len=0 
' 0018     27 LABEL : Cell Value, String Constant - GpDKltlJHvAb len=0 
' 0018     23 LABEL : Cell Value, String Constant - HcKtAxrM len=0 
' 0018     24 LABEL : Cell Value, String Constant - HwmfWiLCZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - JMPEHFhSH len=0 
' 0018     22 LABEL : Cell Value, String Constant - lHXFdpr len=0 
' 0018     21 LABEL : Cell Value, String Constant - LqAlpu len=0 
' 0018     27 LABEL : Cell Value, String Constant - lRcZcHiMVCiY len=0 
' 0018     21 LABEL : Cell Value, String Constant - MsCpCW len=0 
' 0018     26 LABEL : Cell Value, String Constant - MzdhNsGsOrk len=0 
' 0018     24 LABEL : Cell Value, String Constant - OsDksvVSo len=0 
' 0018     22 LABEL : Cell Value, String Constant - oTdKZlo len=0 
' 0018     27 LABEL : Cell Value, String Constant - pmniXtHlwIkO len=0 
' 0018     23 LABEL : Cell Value, String Constant - PrIjMYTR len=0 
' 0018     21 LABEL : Cell Value, String Constant - rMYeRY len=0 
' 0018     20 LABEL : Cell Value, String Constant - rVtQG len=0 
' 0018     20 LABEL : Cell Value, String Constant - ttspT len=0 
' 0018     25 LABEL : Cell Value, String Constant - WPTVltWgBn 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)

Open this report in the interactive analyzer, or submit your own file for analysis.