Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ca9377dd51e66bfa…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:46:48 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 69c2077c0ee97570ce5f03a18811546c SHA-1: 4dd4d58b842f15035e9674d38e153226227a00e2 SHA-256: ca9377dd51e66bfa64eef6aecdff78079e60bfb34e686e9b592c3357a2494b34
140 Risk Score

Malware Insights

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

The file contains an Excel 4.0 macro sheet with an Auto_Open defined name, indicating it will execute automatically upon opening. Heuristics confirm the presence of dangerous formula APIs, specifically related to execution, suggesting the macro is designed to run malicious code. The macro's intent is to execute arbitrary code upon opening the document.

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: 50456a39eea5e65a0ccc54afc88edc65f20744f5eb5464fe41777d6f4bbd654b
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  ZBtsIteeben
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C147 
' 0018     20 LABEL : Cell Value, String Constant - bRtMH len=0 
' 0018     22 LABEL : Cell Value, String Constant - cFhYcBd len=0 
' 0018     27 LABEL : Cell Value, String Constant - cHMlzeyLZlcL len=0 
' 0018     22 LABEL : Cell Value, String Constant - fdprbVk len=0 
' 0018     23 LABEL : Cell Value, String Constant - FluSBqUk len=0 
' 0018     21 LABEL : Cell Value, String Constant - GtkTii len=0 
' 0018     21 LABEL : Cell Value, String Constant - HvTqjT len=0 
' 0018     20 LABEL : Cell Value, String Constant - Iqfad len=0 
' 0018     25 LABEL : Cell Value, String Constant - iYgNYfVtFR len=0 
' 0018     27 LABEL : Cell Value, String Constant - jFXnFwArTCGO len=0 
' 0018     27 LABEL : Cell Value, String Constant - NNVdbjBfcrLa len=0 
' 0018     22 LABEL : Cell Value, String Constant - oPCQgDV len=0 
' 0018     25 LABEL : Cell Value, String Constant - TiAwSfylyO len=0 
' 0018     26 LABEL : Cell Value, String Constant - TWOevbpaLAL len=0 
' 0018     24 LABEL : Cell Value, String Constant - UUBFaukhF len=0 
' 0018     23 LABEL : Cell Value, String Constant - vsMgDNLN len=0 
' 0018     22 LABEL : Cell Value, String Constant - wOaFtaQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - xhxcvtuz len=0 
' 0018     22 LABEL : Cell Value, String Constant - XQbnuAi len=0 
' 0018     27 LABEL : Cell Value, String Constant - zaUQGBiqnTkw 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)