Malicious PDF — malware analysis report

Static analysis result for SHA-256 c90b58bea933eb43…

MALICIOUS

PDF

83.4 KB Created: 2021-08-21 22:18:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c9a6bc7050e12dc76ccfa75be7c09dad SHA-1: 383cecaba6de8e915f69079290a0a35327d154e5 SHA-256: c90b58bea933eb43db5ec5f6de8ac949f831dc678de9f6071377a49a6db6a7a3
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute phishing content or malware. The presence of multiple links to potentially compromised sites reinforces the phishing and distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://nguoixunghekiev.vn/userfiles/file/damesigi.pdf In PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/30630137065.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/n18h89h269pem5b56qeh880aj5/833612873.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/6aa49cc814248348a9e5c062f7752aab/dubibebeve.pdfIn PDF document text
    • http://lagostena.it/userfiles/files/jagekemizutubiwuvu.pdfIn PDF document text
    • http://duoctruongxuan.vn/userfiles/image/file/woveboruvaxo.pdfIn PDF document text
    • https://bostoncake888.com/UserFiles/files/xonibapimajiruwajolira.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/c2605ab34ebda36b7c1adf2fb036155e/lerinasukagelikoto.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f0459077fcf---fitalowixizuzodufigux.pdfIn PDF document text
    • http://sattamatkapatti.com/userfiles/file/53863773624.pdfIn PDF document text
    • https://cylinder96.ru/admin/ckfinder/userfiles/files/9901815805.pdfIn PDF document text
    • http://www.kymenhome-etsinta.net/tiedostot/files/zinudefal.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/62435070454.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/cqn390qgkc5h013frq5gcl7dc1/garapukelukojujijojuvej.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082cbb0e5d77---37076449935.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf51a641d3---bufiwuveziresuj.pdfIn PDF document text
    • http://librojuridico.com/aym_images/files/16698076054.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/pamuvori.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/vvmjrpn9l4uvqam76otc0codv2/34329755093.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/7kbt6e3hg9h09iqr0brekmmopv/kubodeziwebomizozuxaj.pdfIn PDF document text
    • http://datev.hu/ckfinder/userfiles/files/lupeg.pdfIn PDF document text
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/87860073594.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16217241443853.pdfIn PDF document text
    • http://tortsurprise.ru/upload/redactor/files/41212531858.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=what+is+the+predominant+intermolecular+force+in+ch3ohPDF 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_off0000e086.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE086 16884 bytes
SHA-256: 2d4c61bbe45fe8af3d2e0133e5a3429303d695de850fb427ae2ef1ea7b59f42c
font_01_sfnt_off00010c58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C58 11152 bytes
SHA-256: 1baa90f659962562054e944da8b775ea373094555bb1b707ced20484da4f8c5b
font_02_sfnt_off00012641.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12641 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1