Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 219331ec398477db…

MALICIOUS

Office (OOXML)

26.4 KB Created: 2021-08-18 02:04:39 UTC Authoring application: Microsoft Excel 16.0300
MD5: 43912724c0d9e4e2f310b55d7ea3aea6 SHA-1: cd62ddea534920daa6e7ff7fc4db2d2ffc0b9f29 SHA-256: 219331ec398477dbd1f177cb584166c3ac42535beac93cd8269ce3a0ad5bb352
610 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File T1071.001 Web Protocols

The sample contains VBA macros that execute automatically upon opening. These macros use WScript.Shell and CreateObject to download a file from the embedded URL 'http://ec2-18-184-17-12.eu-central-1.compute.amazonaws.com/standardchartered/passleak/180821/' and save it as 'Details.dat' in the temporary directory. The document body suggests a password leak notification, likely a lure to encourage the user to open the malicious document and trigger the macro execution.

Heuristics 14

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • Obfuscated VBA Shell command with URL critical OLE_VBA_OBFUSCATED_SHELL_URL
    VBA macro invokes Shell with command text assembled through decoder or string-manipulation functions and includes a URL. This is a high-confidence downloader/dropper pattern, stronger than Shell or URL evidence on their own.
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
  • ClamAV: Doc.Downloader.Valyria-10026858-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Valyria-10026858-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject 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.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://ec2-18-184-17-12.eu-central-1.compute.amazonaws.com/standardchartered/passleak/180821/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
6f10dbfd178df5efd238bf6a8517af77f1bf3a82e4a72ff54e2bcbf6ac74b4aa
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 4717 bytes
vbaProject_00.bin
7f6edb95c82316ccdad0ac5b4007c239a249fa63d7904990eecfee1b1485b010
vba-project OOXML VBA project: xl/vbaProject.bin 18432 bytes
Detection
ClamAV: Doc.Downloader.Valyria-10026858-0
Obfuscation or payload: unlikely