Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2df9b42b5f5cbfdb…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:44:15 Authoring application: Microsoft Excel First seen: 2021-09-29
MD5: 7f217bb32d8af1e6ca40598ad19af5c4 SHA-1: 3e23610cfd8416ba1bb5256419456b4b6031f026 SHA-256: 2df9b42b5f5cbfdba075910b2abd40066a1805342d9da4efdb477d76ce5e6b2d
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open macro. This macro is flagged as dangerous due to its use of formula APIs, including the RUN function, indicating it's designed to execute arbitrary commands. The presence of the Auto_Open entry strongly suggests the macro will execute automatically when the workbook is opened, likely to download and execute a secondary 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) 6413 bytes
SHA-256: b1c00c461095aeeeea0b4e03d83ab5b51040e1ce6cbec0a3db26f6971cb42732
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 -  KjszZ
' 0018     25 LABEL : Cell Value, String Constant - ajvPDHFQYf len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F182 
' 0018     23 LABEL : Cell Value, String Constant - AWjdAbBf len=0 
' 0018     23 LABEL : Cell Value, String Constant - BfOeEwIO len=0 
' 0018     20 LABEL : Cell Value, String Constant - bwohe len=0 
' 0018     21 LABEL : Cell Value, String Constant - CjZCEk len=0 
' 0018     21 LABEL : Cell Value, String Constant - JmXBlQ len=0 
' 0018     27 LABEL : Cell Value, String Constant - mUReaRrfgKXJ len=0 
' 0018     25 LABEL : Cell Value, String Constant - NadFQAXHfD len=0 
' 0018     21 LABEL : Cell Value, String Constant - nCWKxo len=0 
' 0018     27 LABEL : Cell Value, String Constant - pEJRwMiBlbLy len=0 
' 0018     20 LABEL : Cell Value, String Constant - rdMBh len=0 
' 0018     20 LABEL : Cell Value, String Constant - rNaEx len=0 
' 0018     21 LABEL : Cell Value, String Constant - ryeaWK len=0 
' 0018     21 LABEL : Cell Value, String Constant - sBVoqY len=0 
' 0018     27 LABEL : Cell Value, String Constant - vKqVfEvJahTO len=0 
' 0018     22 LABEL : Cell Value, String Constant - vmDjhWA len=0 
' 0018     24 LABEL : Cell Value, String Constant - XDupBfHut len=0 
' 0018     21 LABEL : Cell Value, String Constant - YFDeQa len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZeJvMi len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZignBWMZ 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 : Cel
... (truncated)