Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 676435953002025d…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:28:20 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: efc546dd60327c3527d980fd0021a51f SHA-1: d8f1e883475d26911539c07a87a931078d62afc5 SHA-256: 676435953002025d27e8da7695afb63846dacf7c623e3b6a8e24731c010c1439
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known method for executing malicious code upon opening the workbook. The critical heuristic firings indicate the presence of dangerous formula APIs within the Auto_Open macro, suggesting an attempt to run arbitrary commands or download further payloads. The exact nature of the payload is not discernible from the provided evidence, but the mechanism points to a macro-based execution.

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) 6690 bytes
SHA-256: 18a2fa6839c8ce323d52518f42eb9fb0a2a8cf448d56b620a200184bd3f41249
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  XPWzanog
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B146 
' 0018     23 LABEL : Cell Value, String Constant - AVTaMWvA len=0 
' 0018     21 LABEL : Cell Value, String Constant - dMQsES len=0 
' 0018     25 LABEL : Cell Value, String Constant - fCBUPEbHKi len=0 
' 0018     27 LABEL : Cell Value, String Constant - FJkHSinxmLXT len=0 
' 0018     22 LABEL : Cell Value, String Constant - gTnwXzs len=0 
' 0018     24 LABEL : Cell Value, String Constant - gWLlhYbXD len=0 
' 0018     26 LABEL : Cell Value, String Constant - HjGDnvsPpLr len=0 
' 0018     26 LABEL : Cell Value, String Constant - KKIPiELyaMI len=0 
' 0018     20 LABEL : Cell Value, String Constant - kovHU len=0 
' 0018     27 LABEL : Cell Value, String Constant - kYELzhhKmuvj len=0 
' 0018     21 LABEL : Cell Value, String Constant - LlKvNS len=0 
' 0018     24 LABEL : Cell Value, String Constant - moYurNMot len=0 
' 0018     23 LABEL : Cell Value, String Constant - NfyBziLL len=0 
' 0018     25 LABEL : Cell Value, String Constant - OUVpDStHLZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - owRzVEwqxDsr len=0 
' 0018     23 LABEL : Cell Value, String Constant - piVBixTt len=0 
' 0018     26 LABEL : Cell Value, String Constant - PKPTwLWcGNJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - qhaGeoyx len=0 
' 0018     23 LABEL : Cell Value, String Constant - RadLkauh len=0 
' 0018     26 LABEL : Cell Value, String Constant - wkZWdJyUFSg 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/ 
... (truncated)

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