Malicious PDF — malware analysis report

Static analysis result for SHA-256 853df9e8c7bfd49a…

MALICIOUS

PDF

83.5 KB Created: 2021-08-25 20:15:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ba32d82dc50501fed2469c6f913bd10b SHA-1: 497c0cef0601d23349a3e2db62079fd8536e761f SHA-256: 853df9e8c7bfd49a9d1e11d4842df4ec987035d2bba9beefef9f5eb149cee47e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to obscure malicious destinations. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and link farm heuristics point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://www.climatisur.com/ckfinder/userfiles/files/44196815329.pdf In PDF document text
    • http://rent2day.ca/ci2/userfiles/files/fetemokur.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/nozolusonejegizeru.pdfIn PDF document text
    • http://enjoybowlramenandpoke.com/uploads/files/wixon.pdfIn PDF document text
    • http://bkmarine.net/ckfinder/userfiles/files/1627010165.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/22o3jnpqreraei4do7pdpugiha/dabimisuzaxeme.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f7dbd2032---kugejadakuma.pdfIn PDF document text
    • http://ecohouse-lab.com/userfiles/file/keravurisemogu.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/sosomiror.pdfIn PDF document text
    • http://pnktools-th.org/ckfinder/userfiles/files/refenosugosir.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/josikikera.pdfIn PDF document text
    • https://fototipia.hu/files/files/79550440846.pdfIn PDF document text
    • http://clinicaveterinariagoitese.it/userfiles/files/nogogufojuseniwa.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/5dad8e243b017d4c3a8bbb48562c8192/5617039477.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/futozuvesonizomaz.pdfIn PDF document text
    • http://chayka-svg.ru/files/dutidexodir.pdfIn PDF document text
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/jizofoterokusutuwino.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/faxopa.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16110b7fec77d8---pixaxumix.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/aouup7b0gsnj2ukp2tpinh1e21/46101845917.pdfIn PDF document text
    • http://zhodnoceni-penez.cz/is/images/FCKeditor/File/zebuzanitumejipozu.pdfIn PDF document text
    • https://proxus.nl/file/nikafipegu.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/617c2047d0f26fe041be7b7f8dc282be/kegizomorakixozoguv.pdfIn PDF document text
    • https://masukpt1.com/contents//files/39065084635.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/64d0b481aaddfd55202503b0364127e5/saperuji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=maths+one+word+questions+and+answersPDF 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_off0000e306.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE306 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB1D 10624 bytes
SHA-256: ed767f7549b236d96b9ebf19526f4b103e31d48f85ce07dc542a35a1141a6087
font_02_sfnt_off00011338.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11338 16996 bytes
SHA-256: 85aeb6aaefd3f0a6858b306904224deb1f9a73621868bc79adb16d5844c17381