Malicious PDF — malware analysis report

Static analysis result for SHA-256 11a42916a45f41a8…

MALICIOUS

PDF

96.4 KB Created: 2021-09-13 06:31:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c3953a32807ba31aa503b51ac291b5e2 SHA-1: f6b1abebc3a5674801ea7a426b5cd5baab80dba4 SHA-256: 11a42916a45f41a827b933c2e784616c37b04df81f53724785ba73652baca466
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a ML classifier and ClamAV, indicating it's a phishing or trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload directories, suggesting a tactic to host malicious content or redirect users to phishing sites. The presence of a link farm on disposable hosting further supports a malicious intent to distribute links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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 http://zhongjiukeji.com/upload_fck/file/2021-9-2/20210902013047194308.pdf In PDF document text
    • http://enslev-anlaegsservice.dk/userfiles/file/weponasopibupazujiran.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/e9872323bf821038affb2d60d311d0ac/79215472751.pdfIn PDF document text
    • https://bushregenerators.biz/userfiles/files/wojowujemibefezeteruka.pdfIn PDF document text
    • http://ahnil.com/userData/board/file/lopef.pdfIn PDF document text
    • http://poledance-chrudim.cz/files/file/xesexojunasulukifikazad.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139f981681ac---nadidudigisuvonefiron.pdfIn PDF document text
    • http://sevinctekstil.com/resimler/files/47867946945.pdfIn PDF document text
    • http://tecsun-moscow.ru/docs/file/nidurupokugositono.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/1cd6aa98d752ce4842877e1ef1d65822/35759718024.pdfIn PDF document text
    • https://alperbehang.nl/userfiles/file/rebapipiwanel.pdfIn PDF document text
    • http://emilymillerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zaruped.pdfIn PDF document text
    • http://www.chp.pl/ckfinder/userfiles/files/50220093823.pdfIn PDF document text
    • https://alistairmills.com/ckfinder/userfiles/files/86658050696.pdfIn PDF document text
    • http://k12kos.com/ckfinder/userfiles/files/tiwunabov.pdfIn PDF document text
    • http://saraya-shop.ru/upload/files/dufijubodidodozubomufut.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/f958109d892dd457b647c7b4a8b682b5/4948342236.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/texuru.pdfIn PDF document text
    • https://efficimm.fr/userfiles/files/46150739123.pdfIn PDF document text
    • http://hangquangauto.com/files/ropivinonur.pdfIn PDF document text
    • http://cancunday.com/travela/img/files/69053920592.pdfIn PDF document text
    • http://trustarshida.co/cache/fck_files/file/14358622253.pdfIn PDF document text
    • https://www.abandassociates.com/ckfinder/userfiles/files/38539714554.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=can+i+remove+root+on+androidPDF 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_off00011641.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11641 17856 bytes
SHA-256: 1bc413b14e31e4aad2263902058dd9fc0e2974b59c1973e3554f328d567e1787
font_01_sfnt_off00014482.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14482 10292 bytes
SHA-256: 84f1c8781804ec1e0c83e1f72cb1e4d18a25c1e5dc00b7003b9d680f19b2b60b
font_02_sfnt_off00015bb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15BB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1