Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8db21aff3f32f88…

MALICIOUS

PDF

92.6 KB Created: 2021-06-28 08:30:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: d701b731c5ca151a03bff95ca2627d69 SHA-1: 5bc04e304558e2f69b8a3508be4f20f51f44fd21 SHA-256: d8db21aff3f32f8815828bbde0f104e9b37f54def2d5c47e5c456b076429b699
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of embedded URLs and the nature of the heuristics strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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.
  • 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.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c164b1b4406---38885225205.pdf In PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/923ab13c9cf22d1a6e789f96c2927de6/46458201511.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160745df1c994b---69166130199.pdfIn PDF document text
    • http://shihtzufurbabies.net/clients/d/d3/d383cf0c90cf2d2391705d5438694b4c/File/56700672272.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a580b9b620d---35438908266.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d4156cc0665---74359245485.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/82042138037.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8fe4fb516f---wazunukuxamoloxajiwus.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a03906ef45d---nizoditiforumesosalivawi.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/jetusokesutomepejatizeba.pdfIn PDF document text
    • http://runningrhinelanderrabbitry.com/clients/875187/File/67082731540.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/is13rqc0n6p2gir6egh1pj5v82/62650636640.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608080eabd88c---42697866127.pdfIn PDF document text
    • http://goref.ru/files/file/tedinewupur.pdfIn PDF document text
    • https://traonguoc.vn/wp-content/plugins/super-forms/uploads/php/files/2ceku5kdmatgcqib98fabtco4o/jevegakutibuxapogumawod.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b65cba2809a---61109330107.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160aec9d074869---17503274570.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc3b2ee8df---5239442932.pdfIn PDF document text
    • https://indobaliart.com/sitefiles/file/muveranopazujog.pdfIn PDF document text
    • https://alihuata.com/userfiles/file/pagugufujemoxetidox.pdfIn PDF document text
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/lipagomumovutew.pdfIn PDF document text
    • http://belgium-ex.com/images/blog//file/75990014526.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/mq7155u61fgg7i8rn80u7iv0j4/waxizigiri.pdfIn PDF document text
    • http://ototavandosemesi.com/resimler/file/zurogupixebes.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=plaintive+in+courtPDF 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_off00010748.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10748 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011f5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F5A 17336 bytes
SHA-256: ecb51ca11f5086aec68d60c6170bbf4d06a9ebc9ce94c925de4dfe90f07706a6
font_02_sfnt_off00014cc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CC7 10224 bytes
SHA-256: 6eccc122d037e1d8db318d7772b279753d40ca786d018268cb157b3e658aadb3