Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3643f7c0e3db244…

MALICIOUS

PDF

68.5 KB Created: 2021-09-24 17:44:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e3a7d6a9e8315ec9b1e70979b2f252db SHA-1: 0aa14fd22374dd4c82ecf86a5ad342fe0a596848 SHA-256: c3643f7c0e3db244bef9ff5a6370819ef96a096c7b16a945d5b8d8dfa1a7168a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple disposable domains, which is a common tactic for phishing or distributing further malware. The presence of numerous unknown URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://doxity.ro/ckfinder/userfiles/files/viledujirelufup.pdf In PDF document text
    • http://papaicountrylodge-longstay.com/user_img/files/13051441550.pdfIn PDF document text
    • https://harom.ro/files/file/pizakod.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/xujogagixanupum.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/i4do1b7bn37ug90bvdg4fu1gia/13872838935.pdfIn PDF document text
    • http://lynxitservices.com/ckfinder/userfiles/files/55441782236.pdfIn PDF document text
    • http://allier.proximeo.com/ckfinder/userfiles/files/26814933693.pdfIn PDF document text
    • http://basse-normandie.annuaire-regional.com/ckfinder/userfiles/files/kerewatav.pdfIn PDF document text
    • https://asiquim.com/ckfinder/userfiles/files/fadugedanewu.pdfIn PDF document text
    • https://bharatbiodiesel.com/userfiles/file/6676481072.pdfIn PDF document text
    • http://patanjali.zohukum.com/ckfinder/userfiles/files/vurarenowegazemodin.pdfIn PDF document text
    • http://spreewaldpension-luebben.de/meineBilderAlbertGrundschule/file/28607393778.pdfIn PDF document text
    • http://nifaelectronics.com/userfiles/file/20973835865.pdfIn PDF document text
    • http://razzledazzleevents.in/userfiles/file/ligijixubutazokadibov.pdfIn PDF document text
    • https://ntc-container.com/upload/files/xelazexefajida.pdfIn PDF document text
    • http://versobrokers.eu/userfiles/files/92396658470.pdfIn PDF document text
    • https://xn--80aaa1arbfjoe3bzh.xn--p1ai/data/files/32904889365.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1631609508.pdfIn PDF document text
    • http://tischtennis-kiel.de/images/file/32852771545.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/zafitigakile.pdfIn PDF document text
    • https://pitbulllocksmith.com/nbloom/fckuploads/file/zugofopajowinopukav.pdfIn PDF document text
    • http://polaryachtmanufactory.com/res/wysiwyg/file/13481869695.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=is+a+must+synonymPDF 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_off0000b038.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB038 10064 bytes
SHA-256: 3ffa31f3446df577e3da8f2b57c9edd6362e8259dab9b32da7734ac30d31d665
font_01_sfnt_off0000c6aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6AA 14956 bytes
SHA-256: 93945f269bd08be355745f7f5f9d95a57c9332fdcb49091b768efb36e98b9666
font_02_sfnt_off0000ec7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1