Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f62b348c6eb7751d…

MALICIOUS

Office (OLE)

110.0 KB Created: 2020-07-08 07:27:00 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: 470b9c4bb0640c7072f9fe48b35c7734 SHA-1: e9950db4ebe258417ae7ff5ac9e5eb4e73a5dd80 SHA-256: f62b348c6eb7751d1b89021a0beb75d16c2dee4796e861de524bd3acad10906b
200 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 defined name, which is a critical finding indicating potential malicious execution. The heuristics also indicate the use of dangerous formula APIs and environment evasion techniques. The macro sheet is likely designed to download and execute a secondary payload, though the specific commands are obfuscated.

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 close gate critical OLE_XLM_ENVIRONMENT_EVASION_CLOSE
    Excel 4.0 macro sheet auto-executes environment checks with GET.WORKSPACE / GET.WINDOW, then shows a fake corruption/error message and closes the workbook when the host fails those checks. This is a malware sandbox-evasion pattern, even when the later payload stage is hidden behind obfuscated defined-name flow.
  • 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) 51692 bytes
SHA-256: dff0686279bbd78d322ab436ee53dba7195e34cabb01dc6df868e534b0d5a256
Preview script
First 1,000 lines of the extracted script
' 0085      9 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  
' 0085     27 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  pSxvdSmcThraaNNowK
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     22 LABEL : Cell Value, String Constant - aehYxNG len=0 
' 0018     50 LABEL : Cell Value, String Constant - afndJRSQVszHkxwNRULkzscKNhKOcYHVuuV len=0 
' 0018     52 LABEL : Cell Value, String Constant - aqtwoNcVFnpKmrFPkxlXyVUvdugkLlwqJGcxW len=0 
' 0018     34 LABEL : Cell Value, String Constant - aQvqrpufmtKkkzqskKm len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  !IE54488 
' 0018     43 LABEL : Cell Value, String Constant - BbmgyvSoNFBNesOCLidHJpKPXNsC len=0 
' 0018     53 LABEL : Cell Value, String Constant - bmETablJEhjPWpwmSNOMRDJQhIHXNQIgJomUJd len=0 
' 0018     49 LABEL : Cell Value, String Constant - bmVUItVrESzRDHhVTNfcyVtyvHKZuvFPKn len=0 
' 0018     22 LABEL : Cell Value, String Constant - BxsKIeO len=0 
' 0018     35 LABEL : Cell Value, String Constant - cHiTjnphHjOyuiDtkyJr len=0 
' 0018     21 LABEL : Cell Value, String Constant - CmfmRe len=0 
' 0018     20 LABEL : Cell Value, String Constant - cMtwR len=0 
' 0018     63 LABEL : Cell Value, String Constant - CMuuhUuResZrdhHvsmFCYuTZVgjyUVfojNdvQjdTyHIGLwpw len=0 
' 0018     21 LABEL : Cell Value, String Constant - CxlHwn len=0 
' 0018     25 LABEL : Cell Value, String Constant - cyisyuHXYt len=0 
' 0018     38 LABEL : Cell Value, String Constant - CzFcjqVhhwBEvUjcMtwRtxM len=0 
' 0018     21 LABEL : Cell Value, String Constant - DgwdjD len=0 
' 0018     39 LABEL : Cell Value, String Constant - dgXwZFCkYtjaoyhh
... (truncated)