Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a991a8b242e0e08…

MALICIOUS

PDF

78.9 KB Created: 2021-09-19 08:34:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 1f439dd473574c3f2e34a82b745febfe SHA-1: b1b4dedd6390b069e3c3f7576cddf8adf3f4cc42 SHA-256: 8a991a8b242e0e087da98535892274f2b75ddc6a57f02148cf8f634bfc3b1b64
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and multiple external URIs, with a high ML classifier score and ClamAV detection indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is designed to host numerous links on disposable domains, likely to facilitate phishing or malware distribution. The embedded JavaScript is likely responsible for executing the malicious payload or redirecting the user to a compromised site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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.jindatunnel.com/up_files/file/61248307864.pdf In PDF document text
    • http://fitviewer.de/files/file/motefabobuluxifugad.pdfIn PDF document text
    • https://phoenixturkey.com/upload/ckfinder/files/wumawutikadew.pdfIn PDF document text
    • http://voyagevietnamlaos.com/hinhanh/file/lofixitudapuxatil.pdfIn PDF document text
    • http://pscemetery.com/userfiles/file/1024234339.pdfIn PDF document text
    • https://asiantms.com/ckfinder/userfiles/files/duwejofagemupujetosanufev.pdfIn PDF document text
    • http://zs-oilfieldequip.ru/d/files/2891823838.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-8/20210908172106122897.pdfIn PDF document text
    • http://another-partner.morefriendship.com/upload/files/kimopiwulalilosumisedezo.pdfIn PDF document text
    • http://1carl.com/userfiles/file/ligudujobizuseboforu.pdfIn PDF document text
    • http://www.hro.ait.ac.th/js/ckfinder/userfiles/files/46558115907.pdfIn PDF document text
    • http://studiobardinisrl.com/userfiles/files/suvegegetosigebe.pdfIn PDF document text
    • http://stillincontact.com/images/mails/file/wofir.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/62641845995.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/80903762218.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/15991484067.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132696a2838d---81039220236.pdfIn PDF document text
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/52628162175.pdfIn PDF document text
    • http://adirondackseafood.com/ckfinder/userfiles/files/76237597177.pdfIn PDF document text
    • http://everestlodgelukla.com/userfiles/file/99804858167.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/41283101476.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcc670069a---sididu.pdfIn PDF document text
    • http://casauthienan.com/fckeditor/editor/filemanager/connectors/php/temp/file/18711230958.pdfIn PDF document text
    • http://519pf.com/userfiles/files/93905225781.pdfIn PDF document text
    • http://www.hussco-steel.com/husscofiles/files/vegomubavota.pdfIn PDF document text
    • https://unitytradefze.com/ckfinder/userfiles/files/miwivadujemuwabotiz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=modal+verbs+of+obligation+examplesPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/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://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cece.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCECE 11144 bytes
SHA-256: 5fd875ff5c72837a9e97681a2fa0f43a5496336b1216218b449233a997448e14
font_01_sfnt_off0000e86c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE86C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001007e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1007E 17568 bytes
SHA-256: 70d484b63639e5b84a57f0c75bb6fd8de776dd9569a30fb0598f2e4f6bfd3125