Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd78c846f8b33f15…

MALICIOUS

PDF

71.1 KB Created: 2021-10-02 18:36:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 595854a2e2b277591592391728093b24 SHA-1: 5c3a34130fddc2d53733ffc587eac93add55c32f SHA-256: fd78c846f8b33f155e0296fb593aeee8aab93d361880803ab749002a1c86e490
156 Risk Score

Malware Insights

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

The PDF contains numerous links, with several heuristics indicating it functions as a link farm, including links to compromised CMS upload directories. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or directing users to malicious content. The presence of a Google feedproxy URL, while marked benign, is part of the link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://hongphuc.vn/userfiles/file/nisuf.pdf In PDF document text
    • http://worldwidestationeryholdings.com/files/file/22655706326.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/vitatajusositip.pdfIn PDF document text
    • http://bigyikesmedia.com/home/xtremweb/public_html/consultinstitute/web/upload/files/guremutoloretos.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614c0854d5cb0---dinodolawufe.pdfIn PDF document text
    • http://pallenberg-busreisen.de/uploads/files/rokikabazir.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/wozabixipo.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/h965i4b619soq8k1ts2jui4qaf/93325512789.pdfIn PDF document text
    • https://aldurra.ly/images-editeur/img/file/62790132212.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/70691142791.pdfIn PDF document text
    • https://dentalrud.com/userfiles/file/jubusowuxagiborebi.pdfIn PDF document text
    • https://wupaojichangjia.com/d/files/mibizupedip.pdfIn PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/34209656133.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1614a3835bcbd0---84644250992.pdfIn PDF document text
    • http://gioiacompany.net/images/upload/file/5370441431.pdfIn PDF document text
    • https://sanmuabandoanhnghiep.org/images/content/files/74004798304.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1615825147b1fc---gizezolonotivup.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614bdd0071920---lipapofabavuxivoziwino.pdfIn PDF document text
    • http://satakantaresort.com/user_img/files/9382115323.pdfIn PDF document text
    • https://hotelpancharatna.com/assets/userfiles/files/45788820723.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/40456488354.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/61552496854.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/loguporijakugazuravitiwi.pdfIn PDF document text
    • https://geya99.com/ckfinder/userfiles/files/96398054743.pdfIn PDF document text
    • http://purepoem.com/resource/docContentImg/file/2021-09-21/d716834e0c74729f03b56626f26872d0.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=download+dragon+ball+heroes+episode+1PDF 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_off0000b3f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3F7 15768 bytes
SHA-256: ac017692e1b7d0a37c51fcfa7feefd64c7cce349ab408ffa8d8a4c5231090458
font_01_sfnt_off0000dc0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f421.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF421 10852 bytes
SHA-256: 7b96978686233030eb9adcdf731eed43025db7aa5924a9747f3d0e989f02db67