Malicious PDF — malware analysis report

Static analysis result for SHA-256 71863a5257d87567…

MALICIOUS

PDF

80.2 KB Created: 2021-07-25 17:52:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 6973af0c32bd1a393459130d9cf696e7 SHA-1: 8a697a1a8cdef977ab84a80778e9a7ab58a574c5 SHA-256: 71863a5257d87567c13932af746ffba01970670a380bcc6fb536cc70189d36cb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs and the overall structure indicate the document's purpose is to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • 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://tincorner.vn/uploads/files/38486663010.pdf In PDF document text
    • https://people11people.com/uploads/File/11232404927.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/mliqra3vroq36h4jp1m2vco69u/xigopisamugokanefovo.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b31346cc071---xotidejukekinifoxad.pdfIn PDF document text
    • http://hurtmar.pl/Upload/file/xuletewuxudiwiv.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160835c2d29259---xetexapenogexorobigo.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/27628edc2d7f66a78b10e758e564e0f9/xokugisomipovuzuv.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/15967857377.pdfIn PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/degigenaguwun.pdfIn PDF document text
    • http://computerdoki.hu/user/file/1036707254.pdfIn PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a480dcd0885---jekofoxibisa.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b324a287549---vubozulomum.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b78c46c3566---63284108344.pdfIn PDF document text
    • https://tsegypt.com/file/sagojusonefixa.pdfIn PDF document text
    • http://jikaramen.com/uploads/files/selikegiwonumululamo.pdfIn PDF document text
    • https://xetnghiemadndanang.com/upload/userfiles/files/mufotiradukitot.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/518266ec5ae56a242509ed12549f33cc/jadagagutuperoz.pdfIn PDF document text
    • http://epoxidice.ro/mm/file/66897018998.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160cdd749ba35d---geboletoge.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/b336ed206fa4c13e6aa367a635c93953/numonus.pdfIn PDF document text
    • https://ms01bet.com/contents//files/20521419251.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/4bf7ogkhr4vbbectlotge6e1r6/41058416359.pdfIn PDF document text
    • http://palenice.net/obrazky_clanky/file/dezanugunizugowizuwuxe.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607d9a7472692---55904903075.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=how+do+i+clean+the+filter+on+my+samsung+microwave+model+me18h704sfsPDF 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_off0000d335.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD335 11788 bytes
SHA-256: 3c891bc38b9c14f35851356db11cda30e266a1a2ed69f0820d9dbcf324d9d691
font_01_sfnt_off0000ef29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001073b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1073B 16780 bytes
SHA-256: b40735978c3d98e0531fb175644903d6f48b03557b3d74073b4ce0cf3570209e