Malicious PDF — malware analysis report

Static analysis result for SHA-256 bfcaf72fd79e7606…

MALICIOUS

PDF

97.7 KB Created: 2021-09-20 17:47:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 83d5b9dc875aedd678fd22a6902710aa SHA-1: 875640c5d1cb46c0d1e6a309be59c0f10c9c7537 SHA-256: bfcaf72fd79e7606f0f9de7ebc95d111a195f01ddbdead018be8bc3300da3bc2
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Analysis reveals it functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting. These links are likely intended to redirect users to malicious content or phishing sites, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://photojet.bg/userfiles/file/34051252825.pdf In PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613738d67c34e---nebavofunipawikidawukazod.pdfIn PDF document text
    • http://kemenyseprosiklos.hu/upload/file/45256177341.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/10380670611d265d6234b5088880b3e6/soporigadaraf.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/70595688722.pdfIn PDF document text
    • http://hotelgiottotorino.com/userfiles/files/rigeke.pdfIn PDF document text
    • https://avphunter.ro/ckfinder/userfiles/files/13697105424.pdfIn PDF document text
    • http://immobilieninvestors.com/userfiles/file/8228608547.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/a096f4520e3557c16cc172972d2ec100/28790509388.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/88399566265.pdfIn PDF document text
    • http://brno-skoleniridicu.cz/ckfinder/userfiles/files/zezefadegaseduwaf.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/16283603828.pdfIn PDF document text
    • http://pcserviszlin.cz/ckfinder/userfiles/files/55987393134.pdfIn PDF document text
    • http://floramarble.com/uploads/medapikowufifesudo.pdfIn PDF document text
    • https://hopadive.cz/ckfinder/userfiles/files/bivofafula.pdfIn PDF document text
    • https://togeltop.net/contents/files/37578728270.pdfIn PDF document text
    • http://csc0898.com/userfiles/file/20210918093359_82eb4g.pdfIn PDF document text
    • https://lockerova.eu/admin/upload/documents/89556721034.pdfIn PDF document text
    • https://www.smartfutureexpo.com/ckfinder/userfiles/files/93446238205.pdfIn PDF document text
    • https://psychotherapie-coeppicus.ch/upload/file/jevomozabesadat.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614018a33c9be---41124881156.pdfIn PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/53289697840.pdfIn PDF document text
    • http://erfaspot.com/resimler/files/doxomitenojo.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/2238305438.pdfIn PDF document text
    • http://moscowprice.com/content/xuploadimages/file/4905512255.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=hang+em+high+full+movie+online+freePDF 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_off00011904.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11904 18588 bytes
SHA-256: b826993e42aa9baee95d22600a6ed38cc9ef87d95c151fa787d1088a608b4d0b
font_01_sfnt_off00014a0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A0B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016222.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16222 10552 bytes
SHA-256: d91189c36c0a22d96b844ecdafe9d6fd7da2a149a94153c4fefbe54b271bcf95