Malicious PDF — malware analysis report

Static analysis result for SHA-256 a51b346897d653aa…

MALICIOUS

PDF

94.5 KB Created: 2021-09-21 07:00:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1250341d393f1ee45be48e57bedde888 SHA-1: a1fe878b1eb83e52a15d5dddbb1b692138bcd704 SHA-256: a51b346897d653aa84a12c4547b9e526ccf8ce26266b21d9dfb8bd53bdba066e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be disposable or compromised, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection further support its malicious nature, classifying it as a phishing or trojan PDF. The primary attack pattern involves luring users to click on these links, likely leading to phishing sites or malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9758

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 https://synerhu.ru/uplcv?utm_term=my+hero+academia+movie+two PDF link annotation
    • http://riversedgefm.com/files/file/90910022514.pdfIn PDF document text
    • http://dreamsurgeryen.net/ckupload/files/5985334352.pdfIn PDF document text
    • https://f2h63c2.ip4secure.net/upload/files/76864324593.pdfIn PDF document text
    • http://pasted-radio.de/web/files/51881960519.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/89i28qhrl4e16t5mbct0m7hmm1/ribunetitamisuj.pdfIn PDF document text
    • http://zae.me/datafiles/file/vizenovufeweba.pdfIn PDF document text
    • http://globalcenterhotels.com/bot/ckfinder/uf/files/tekewurobite.pdfIn PDF document text
    • http://pass38.com/images/contentimages/files/ridofipiribugunulakew.pdfIn PDF document text
    • http://cmrivestimenti.com/userfiles/files/zikikupudaxirub.pdfIn PDF document text
    • http://sd-admin.fazendapenaazul.com/ckeditor/uploads/files/33214897916.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/ruvezuxokide.pdfIn PDF document text
    • https://lifecareproduct.in/ckfinder/userfiles/files/44367867806.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/snfu9ip4it8ub2vcnji5lk2mc9/fogoxulolujedexe.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/ac71f4984a68652a35af1bd5fd496aca/25133875495.pdfIn PDF document text
    • https://happyfun.tw/uploads/files/202109180647532518.pdfIn PDF document text
    • https://cncunse.com/d/files/77296434356.pdfIn PDF document text
    • http://gtlmarinefuel.com/userfiles/file/mogaxilijofuze.pdfIn PDF document text
    • https://jackinthegymtpe.com/uploads/files/202109010901041137.pdfIn PDF document text
    • https://www.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/8319423570.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1614072a345e43---22687306116.pdfIn PDF document text
    • https://konteshamamotu.com/userfiles/file/bumediropatogevo.pdfIn PDF document text
    • http://remaining-mc.de/userfiles/file/gadasipifikolegovatajejo.pdfIn PDF document text
    • http://mathrainbow.com/userfiles/file/65035506297.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/dotabepasavos.pdfIn PDF document text
    • https://aahs.givingplan.net/sites/default/files/editor/file/7393024531.pdfIn PDF document text
    • http://parateam.cz/file/binupuxibebimowow.pdfIn PDF document text
    • https://ppuhperspektywa.pl/files/edytor/file/6344508920.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_off000100eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011902.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11902 10576 bytes
SHA-256: bd462dfb551b17177c6392777a0aca087be886495f5b5c781d98c25c59f609d2
font_02_sfnt_off0001313c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1313C 22304 bytes
SHA-256: f202929554306d1849cae341ab4444cc201b0a2db516d78e69cd4baa0d5cf4fa