Malicious PDF — malware analysis report

Static analysis result for SHA-256 33c1f8a80f723f42…

MALICIOUS

PDF

68.7 KB Created: 2021-09-20 11:49:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: feacf7ef6a97834bd219905c00a0ff32 SHA-1: ff208b68041ddfc4e7057d8ee1cbe29b8bbfefac SHA-256: 33c1f8a80f723f42591dfec17a8abda893d883364ca211d533f71d425e187e16
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URI indicators and link farm heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://synerhu.ru/uplcv?utm_term=which+is+the+best+video+downloader+for+android PDF link annotation
    • https://jkmart.net/FCKFiles/File/vaxunaged.pdfIn PDF document text
    • http://katachizu.com/img/news/files/61492993290.pdfIn PDF document text
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/pikudexurulerabaneverarot.pdfIn PDF document text
    • https://tasleemdubai.com/userfiles/files/wugevana.pdfIn PDF document text
    • https://parlagame.com/calisma2/files/uploads/73406431879.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131c2f10869e---lutegejolozugarepugisul.pdfIn PDF document text
    • https://linker.tw/files/12505057650.pdfIn PDF document text
    • http://physocare.com/Images_upload/files/wedotu.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/9804h9j06e4qa6mbd4dcv346fj/pomujarowi.pdfIn PDF document text
    • http://mallenmediations.com/mallenmediations/images/userfiles/file/rotuf.pdfIn PDF document text
    • http://lifecontinues.ru/images/files/zolofiwoxivonarumi.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/755038c376d5686761c4914a2fe02eba/lomoxesironuwo.pdfIn PDF document text
    • https://mbzgogo.xyz/web/img/podborky/files/jafudakuwipotinomolokijo.pdfIn PDF document text
    • https://triosms.com/userfiles/file/sexeliwovinatamugat.pdfIn PDF document text
    • https://egca.fr/userfiles/file/migizarudu.pdfIn PDF document text
    • http://franzoesischebulldoggen.eu/userfiles/file/31669754184.pdfIn PDF document text
    • http://elcolono.net/userfiles/files/85267658485.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/zikoxuwogekojixokuf.pdfIn PDF document text
    • http://free-note.kr/files/fckeditor/file/1549942339613ec6fbe7e76.pdfIn PDF document text
    • http://caogenzhiben.com/filespath/files/20210920153842.pdfIn PDF document text
    • http://aggengr.com/uploads/CMS/file/denosulogaxi.pdfIn PDF document text
    • 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_off0000b02e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB02E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c840.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC840 14292 bytes
SHA-256: 377c0a037bbc29f715916ea6c95c42c6256b701bbe9285e7ef61cf511a4bd9b7
font_02_sfnt_off0000ebc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBC0 10856 bytes
SHA-256: bc56e37ba9c2cc605f1be91694ab039fafabface4033eda5ee8f8c02a355d8e7