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

Static analysis result for SHA-256 ef46033bd20dc2c0…

MALICIOUS

Office (OLE) / .XLS

171.5 KB Created: 2018-12-06 20:43:11 Authoring application: Microsoft Excel
MD5: 2051874c7e07efce49b2f04d09d9ef3f SHA-1: 11ee7464448eef9bc48501076262517b044be575 SHA-256: ef46033bd20dc2c05f66e9bd2e533c9d41419350443b90891e7596d9e56a6365
408 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1059.003 Windows Command Shell

The file contains VBA macros, specifically a Workbook_Open macro, which is a common technique for initial execution. The script utilizes WScript.Shell and the Shell() function to execute commands, indicating it's designed to download and run a second-stage payload. The presence of 'fyf/ddnn' and 'SENDTO' in the script suggests a download path and potential staging location.

Heuristics 10

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • ClamAV: Xls.Malware.Valyria-10032137-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Valyria-10032137-0
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • 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
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
13603f2d6a1798419331da6e76ea6f13739192eabf901e1b0969da2f203d1f72
vba-macro oletools.olevba.extract_macros (decoded VBA source) 54746 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s). Carved artifact contains 126 long base64-like blob(s). Carved macro source contains an auto-exec entry point and execution/download terms.