Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab72dcad04bc834a…

MALICIOUS

PDF

135.9 KB Created: 2021-09-10 20:20:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 936b172c92fe3eeb35d34ad0aebb7857 SHA-1: e922f9e54b2eb6bd107ad830d0aeb465fcdda3df SHA-256: ab72dcad04bc834ae99df27648b49b7476de0a4a3297034b201f8feb02a3a406
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious. It contains a large number of embedded URLs, many pointing to potentially disposable domains, suggesting a link farm or phishing lure. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically indicates a non-clustered link farm on disposable hosting, reinforcing the malicious intent. While no scripts were directly extracted, the nature of the embedded links and the overall detection suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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 http://revistaspontan.ro/assets/ckfinder/core/connector/php/uploads/files/82141005439.pdf In PDF document text
    • https://masterjobintl.com/ckfinder/userfiles/files/bimakaviwidufodelitov.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613226f73cc78---15039304140.pdfIn PDF document text
    • http://pate4me.com/userfiles/file/60293068951.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/68034277692.pdfIn PDF document text
    • http://malopolskiszlakwinny.pl/upload/File/3408917520.pdfIn PDF document text
    • http://suarezbeltran.com/aym_images/files/60494159320.pdfIn PDF document text
    • https://ajur.rest/uploads/userfiles/file/90558821422.pdfIn PDF document text
    • http://paraglider24.de/pics/fotos/1/file/bilelakukanupigevuru.pdfIn PDF document text
    • https://tort-art.ru/userfiles/file/poxowekelimawidafe.pdfIn PDF document text
    • https://landatur.com/files/galeria/files/65627485382.pdfIn PDF document text
    • https://tybistanbul.org/resimler/files/80584226800.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/bonofimepoj.pdfIn PDF document text
    • http://texinpack.com/uploadfile/file///2021090604241040.pdfIn PDF document text
    • http://emke.hu/uploads/ckfinder/userfiles/files/buluxelixusafoduxi.pdfIn PDF document text
    • http://chongthamphucthang.com/images/news/files/luliwizeme.pdfIn PDF document text
    • https://nedimgame.net/calisma2/files/uploads/94534095355.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613275bcb7eee---18861094526.pdfIn PDF document text
    • http://fgosvo.ru/files/files/zugasuvewijudo.pdfIn PDF document text
    • http://universalestetic.com/userfiles/file/xevodebedu.pdfIn PDF document text
    • http://misterholidaysanprisco.it/userfiles/files/mokemotufapurugewar.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/jadanajakufesilej.pdfIn PDF document text
    • http://byty-pardubice.eu/UserFiles/File/gobopilojowevukivomem.pdfIn PDF document text
    • http://icsbc.ru/fuploader/file/57470108036.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/16853161703.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=malleus+maleficarum+t%C3%BCrk%C3%A7e+pdfPDF 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_off0001ab95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AB95 11132 bytes
SHA-256: 27dbd55d8f3011a29ab13ebab3d910253899311ed8da0dcfd97c9f17063322f0
font_01_sfnt_off0001c4f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C4F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001dd07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DD07 20792 bytes
SHA-256: df6a395097f7c0426274f17bb890585f0c340491ee38058f6b1811fb2629a8e5