Malicious PDF — malware analysis report

Static analysis result for SHA-256 d799ec3bd5acb058…

MALICIOUS

PDF

85.1 KB Created: 2021-09-19 08:22:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 51365dac07e421d3037263b04f68475f SHA-1: 1ae92c3250d8185f92b0a45ca3a7e9fa60f2d5c7 SHA-256: d799ec3bd5acb05822a9beedcaaa925e0dc8e0740d90c5f6bbabe10d6b5742d2
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely redirects the user to one of the numerous external URLs, which are often used for phishing or to download further malicious payloads. The presence of many similar URLs suggests a link farm designed to obscure the ultimate destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9938

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://gamboeng.com/assets/ckfinder/userfiles/files/73032839319.pdf In PDF document text
    • https://naucharts.com/ckfinder/userfiles/files/daginigam.pdfIn PDF document text
    • https://nomortiga.com/contents/files/nevifesuvimizo.pdfIn PDF document text
    • https://iieng.org/editor/ckfinder/userfiles/files/pupinitupamigonezivura.pdfIn PDF document text
    • https://butyfarm.mm520.net/userfiles/files/64429983701.pdfIn PDF document text
    • http://cukrarnakolbaba.eu/obrazky/files/59633970206.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/kekusuruxudeniz.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614671fdd8949---85068945099.pdfIn PDF document text
    • http://slabowidzacy.smprzemysl.pl/ckfinder/userfiles/files/28949622493.pdfIn PDF document text
    • http://healhumanity.foundation/userfiles/file/genopesogifini.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/15043762633.pdfIn PDF document text
    • https://artlabjo.com/userfiles/file/zebajigafirebabolironanus.pdfIn PDF document text
    • http://villkasz.hu/editor_up/damapujomusowoxafosatat.pdfIn PDF document text
    • https://congtydaihai.com/upload/files/sujugipamapub.pdfIn PDF document text
    • http://madiran-cruduparadis.fr/ckfinder/userfiles/files/97946250790.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021090402115973499.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/902356751613d5b7a6d4e2.pdfIn PDF document text
    • http://giustizianuova.it/userfiles/file/25540517206.pdfIn PDF document text
    • http://lgassociates.in/uploads/65831715877.pdfIn PDF document text
    • http://praxis-greve-polley.de/web/editor/files/sodoju.pdfIn PDF document text
    • http://leebyunghun.org/new/upload/board/files/bodadajifetugomezatower.pdfIn PDF document text
    • https://sambelteri.com/contents/files/dibojowevibit.pdfIn PDF document text
    • http://vet-arrighicolangelicristilli.eu/userfiles/files/27725582513.pdfIn PDF document text
    • http://mcap.cz/images/uploadedimages/file/89720143733.pdfIn PDF document text
    • https://www.santaterezinha.com.br/js/ckfinder/userfiles/files/rutemuratelazazerumij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+move+files+to+your+sd+cardPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC1C 10888 bytes
SHA-256: c6a6a98706b30dffe9f973c8c9cc221a7c272a08662c8ed739c0a1bd97802e9d
font_01_sfnt_off0000f55c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF55C 1852 bytes
SHA-256: 4a426f9187145098ae4cd9bbff35468ba4737087772778f179f5ab9644148e56
font_02_sfnt_off0000fdff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDFF 18456 bytes
SHA-256: f01015b7fbeb389ea7c2e3c4a56cee59f88e1c94a6eb47028a9337ca995cc877
font_03_sfnt_off00012de2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1