Malicious PDF — malware analysis report

Static analysis result for SHA-256 a781a54f795b6178…

MALICIOUS

PDF

80.7 KB Created: 2021-10-05 15:36:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 71d034c54600710600568ff3a6335b6f SHA-1: f5f693d8079d389ff94e803a89cd340967fa3449 SHA-256: a781a54f795b61780f663427d041d987f71073f64eac38067ccc27661aa4feff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous external links, many pointing to compromised WordPress upload directories or disposable hosting, suggesting a link farm or redirection mechanism. The presence of embedded URLs and the nature of the heuristics indicate the file's primary purpose is to redirect users to malicious external sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://crysiq.ru/uplcv?utm_term=a+short+of+time PDF link annotation
    • https://dongphuchuytai.com/upload/files/77975922022.pdfIn PDF document text
    • http://jamxmpharmatech.com/upload/files/pupesanizojifijapa.pdfIn PDF document text
    • https://gotoko.com/cmsv2/upload/files/kepijapu.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/53080218894.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161440d388e66d---14650476268.pdfIn PDF document text
    • https://www.area-tlc.com/public/ckfinder/userfiles/files/58067881063.pdfIn PDF document text
    • https://mimpishio2.com/contents/files/tiwanezisozibinowexud.pdfIn PDF document text
    • http://xn--80aafkatcapceshpicpg3h.xn--p1ai/pict/file/12043877384.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/6977933931.pdfIn PDF document text
    • https://brillimet.com/uploads/files/202110011104212332.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/b8c65f85d6c7bd148e4ba6d6bc25017a/90202646301.pdfIn PDF document text
    • http://mt-filtration.com/uploaded/file/1883772236613d9d279ddae.pdfIn PDF document text
    • http://productinfo.in/konadnew/userfiles/file/turomixaka.pdfIn PDF document text
    • http://inica.org/files/file///54745024370.pdfIn PDF document text
    • https://promenade-perpignan.com/userfiles/file/83842095718.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/4bec703c8eaf4e8a655b20eba2be9715/selomiwifujo.pdfIn PDF document text
    • http://gavionescodeinsa.com/userfiles/7489677437.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/murujibakonub.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd4d1afb5c---44061088274.pdfIn PDF document text
    • http://theemasternetworker.com/ckfinder/userfiles/files/javajokuxozufaxekibezasob.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/8450300277.pdfIn PDF document text
    • 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_off0000d365.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD365 19988 bytes
SHA-256: 9d4511d9c639368948ac33f4931fde752cc29ece7a164bf87523812b4d630a17
font_01_sfnt_off0001075c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075C 10148 bytes
SHA-256: 6d0ed3bc55c31f2e45ab08bd82ef7209003b3028150b064701a0a38f7189c637
font_02_sfnt_off00011e1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1