Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2eb15ec8c57b8985…

MALICIOUS

Office (OLE)

253.0 KB Created: 2020-07-29 08:41:54 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: 0c1c57ed7f936d1555038290e593559a SHA-1: 0396d282b0932027c34ed07e90d75c59bb76059a SHA-256: 2eb15ec8c57b8985bb4188b6a15bc3d78a8252f5620151edd6512b643f4b03f3
240 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open macro. Heuristics indicate the presence of dangerous API calls and environment evasion techniques within the macro. The document body prompts the user to 'Enable Editing' and 'Enable Content', which is a common lure for macro-based malware. The ClamAV signature also points to a dropper agent.

Heuristics 5

  • ClamAV: Xls.Dropper.Agent-9159657-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-9159657-0
  • 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.
  • XLM Auto_Open environment-evasion HALT gate high OLE_XLM_ENVIRONMENT_EVASION_HALT
    Excel 4.0 macro sheet auto-executes multiple GET.WORKSPACE / GET.WINDOW environment checks and halts execution when the host does not match the expected user environment. This is a common sandbox-evasion pattern in XLM malware and is stronger than a bare XLM macro-sheet indicator.
  • 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) 270267 bytes
SHA-256: 01ccf1f5b5c9cec08f70c136952a47a53b6ead811ec7f51459e68a3d71aad332
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  cd4iG
' 0018     27 LABEL : Cell Value, String Constant -       hidden len=7 ptgRef3d  Sheet!FN5474 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgNameX  NAMEIDX 1 
' 0018     27 LABEL : Cell Value, String Constant - awJIVBeaixMU len=0 
' 0018     27 LABEL : Cell Value, String Constant - durprdHgWMwR len=0 
' 0018     20 LABEL : Cell Value, String Constant - eycGB len=0 
' 0018     25 LABEL : Cell Value, String Constant - gjFsWyxaSV len=0 
' 0018     26 LABEL : Cell Value, String Constant - IBqwjpHhbDk len=0 
' 0018     25 LABEL : Cell Value, String Constant - JmuwmIJRnZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - qgjdtYSE len=0 
' 0018     22 LABEL : Cell Value, String Constant - rVeYtRt len=0 
' 0018     21 LABEL : Cell Value, String Constant - UukwDj len=0 
' 0018     22 LABEL : Cell Value, String Constant - Vlggtrm len=0 
' 0018     20 LABEL : Cell Value, String Constant - WXLli len=0 
' 0018     22 LABEL : Cell Value, String Constant - XIybOGN len=0 
' 0018     23 LABEL : Cell Value, String Constant - xlaGeMOb len=0 
' 0018     25 LABEL : Cell Value, String Constant - XLQQpEdtGd len=0 
' 0018     20 LABEL : Cell Value, String Constant - zJjUd 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 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 : 
... (truncated)