Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 caa1d5d7683eaa94…

MALICIOUS

Office (OLE)

259.0 KB Created: 2020-08-05 10:17:47 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: d3bea5365302657f53f3cfda5a8e6129 SHA-1: 44a47d9f8063c8cffe1e1534605105c43b461cd5 SHA-256: caa1d5d7683eaa9467308cfa56cf4b6ef7935dc48f66f652cef3d368b1978d45
180 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open macro. The document body displays a social engineering lure to "Enable Editing" and "Enable Content", which is a common tactic for macro-based malware. The presence of the Auto_Open macro and the dangerous formula API (RUN) indicates that the macro is designed to execute automatically upon opening, likely to download and run a second-stage payload.

Heuristics 4

  • 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) 266160 bytes
SHA-256: 14193bd3df17229868aeaa6771e66542f9bd18e32e0a41e322d0f0165488afe9
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 -  zca0Q
' 0018     21 LABEL : Cell Value, String Constant - ATsObm len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgNameX  NAMEIDX 7 
' 0018     25 LABEL : Cell Value, String Constant - aZuUbDXpbx len=0 
' 0018     21 LABEL : Cell Value, String Constant - bzTSsc len=0 
' 0018     25 LABEL : Cell Value, String Constant - DripYjutWN len=0 
' 0018     26 LABEL : Cell Value, String Constant - evWteQAyalQ len=0 
' 0018     29 LABEL : Cell Value, String Constant -         hidden len=7 ptgRef3d  Sheet!DI7618 
' 0018     20 LABEL : Cell Value, String Constant - gWMrb len=0 
' 0018     22 LABEL : Cell Value, String Constant - KLRBRCK len=0 
' 0018     21 LABEL : Cell Value, String Constant - kRetIi len=0 
' 0018     25 LABEL : Cell Value, String Constant - LwApBxkSKX len=0 
' 0018     27 LABEL : Cell Value, String Constant - rTkfFvuPEqjO len=0 
' 0018     26 LABEL : Cell Value, String Constant - rVMncjOEOuY len=0 
' 0018     21 LABEL : Cell Value, String Constant - weZukv len=0 
' 0018     21 LABEL : Cell Value, String Constant - yGRyhg len=0 
' 0018     27 LABEL : Cell Value, String Constant - ySILiQeddqIO len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZRwRTBj 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 LABELSS
... (truncated)