Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b690dab2e370b0b2…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:39:54 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: 765928a132ffd0e0a151bef2fe3293d3 SHA-1: 06de266033bc4b3df1e5606c129743482f0c6afe SHA-256: b690dab2e370b0b28c05b062dadbc9b964371778fdc3ffaed9b4363ef1aa1695
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open function, which is a known method for executing malicious code. The presence of dangerous formula APIs like RUN indicates an intent to execute arbitrary commands. The macro sheet itself contains a large amount of obfuscated data, suggesting it's designed to hide its malicious payload.

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) 6558 bytes
SHA-256: 103fb7ced5de7792aa1808383464752ffe051c261546937e27125b145ed254bc
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  AbeReguvB
' 0018     22 LABEL : Cell Value, String Constant - amMxEwM len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H181 
' 0018     22 LABEL : Cell Value, String Constant - bpfScsL len=0 
' 0018     25 LABEL : Cell Value, String Constant - BpJocLwetx len=0 
' 0018     24 LABEL : Cell Value, String Constant - BuKIJWdEH len=0 
' 0018     23 LABEL : Cell Value, String Constant - DYREdQnO len=0 
' 0018     21 LABEL : Cell Value, String Constant - ESsukV len=0 
' 0018     21 LABEL : Cell Value, String Constant - GfRwuR len=0 
' 0018     21 LABEL : Cell Value, String Constant - ggLliC len=0 
' 0018     23 LABEL : Cell Value, String Constant - HdwFnisf len=0 
' 0018     21 LABEL : Cell Value, String Constant - HGkFNt len=0 
' 0018     23 LABEL : Cell Value, String Constant - KOSuKjYG len=0 
' 0018     26 LABEL : Cell Value, String Constant - osZuRLTYDtx len=0 
' 0018     23 LABEL : Cell Value, String Constant - pUiEYxto len=0 
' 0018     25 LABEL : Cell Value, String Constant - rLBgMNwiWU len=0 
' 0018     27 LABEL : Cell Value, String Constant - SyedvXTpYGoB len=0 
' 0018     25 LABEL : Cell Value, String Constant - tBXcQVeAZj len=0 
' 0018     26 LABEL : Cell Value, String Constant - ueVKKOtFfnP len=0 
' 0018     21 LABEL : Cell Value, String Constant - xNgWkF len=0 
' 0018     27 LABEL : Cell Value, String Constant - XWddYXmmDFYy len=0 
' 0018     20 LABEL : Cell Value, String Constant - yDcQA 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)

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