Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 20aa2a67af405894…

MALICIOUS

Office (OLE) / .XLS

105.5 KB Created: 2021-12-29 06:52:36 Authoring application: Microsoft Excel
MD5: c9240798810d1e69b8ed4bf21b95ed89 SHA-1: 640927904a1d0a04c68c98b32eb38294afef31b5 SHA-256: 20aa2a67af405894c69adf05c5d8ac10be044203702eb11c58b5f0dfd9abe66d
300 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File T1105 Ingress Tool Transfer

The Workbook_Open macro is triggered upon opening the Excel file. It constructs a path to 'putty.exe' and then proceeds to execute a series of commands, likely to download and run a second-stage payload. The use of Shell() calls and CreateObject indicates a downloader functionality. The ClamAV detection name 'Doc.Downloader.DocuSign04220-9942585-0' further supports this assessment.

Heuristics 7

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • ClamAV: Doc.Downloader.DocuSign04220-9942585-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.DocuSign04220-9942585-0
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
665f09781fb250e14f44733a22419dd8ce9101e4657189e6d85b9b27b07ab03f
vba-macro oletools.olevba.extract_macros (decoded VBA source) 9447 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 99 Chr/ChrW string-construction calls. Carved macro source contains an auto-exec entry point and execution/download terms.