Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 5622570b0c88fb5e…

MALICIOUS

Office (OOXML)

28.5 KB Created: 2021-08-18 02:04:39 UTC Authoring application: Microsoft Excel 16.0300
MD5: db90384c73a7d82d8661c618a9b24e4c SHA-1: dc5ee276ac43ad1b16e97e068674edf88d26f155 SHA-256: 5622570b0c88fb5ea72e167fd142d5f60526df25247ad1ae938bf350c6d6b0c3
610 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File T1071.001 Web Protocols T1190 Exploit Public-Facing Application

The sample is an Excel document containing obfuscated VBA macros that execute upon opening. These macros leverage WScript.Shell and WMI to download a second-stage payload from the provided URL, saving it to the temporary directory as 'Details.dat' and 'TEDetails.dat'. The script then attempts to execute this downloaded payload, indicating a downloader functionality.

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/employees/incident/180821/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
200ca198abf721cf6f51db4af9e6da67163eae2a05dc55d6ed8ebd2e4f051153		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 4726 bytes
vbaProject_00.bin
0765630e78ed2e42169e69b6076ecf6fe3333d615c55ddab753cf5ce7f248929		 vba-project OOXML VBA project: xl/vbaProject.bin 18432 bytes
Detection
ClamAV: Doc.Downloader.Valyria-10026858-0
Obfuscation or payload: unlikely

Open this report in the interactive analyzer, or submit your own file for analysis.