Malicious PDF — malware analysis report

Static analysis result for SHA-256 b539c0406c91f870…

MALICIOUS

PDF

76.4 KB Created: 2021-09-10 18:55:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c7ca41eaa2f2934d9da6e9b86534cad4 SHA-1: 27dc2573f9be998307943e6709809e67fc30b963 SHA-256: b539c0406c91f87042fabfcabf95fe31edacbeb8e2f042efca4f26be896e9cf6
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised websites or disposable hosting. The document body is unreadable, but the overall structure and URL patterns suggest a lure to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://shipnhanh247.vn/asset/files/16681260552.pdf In PDF document text
    • http://fluitec.fr/ressource/site-image/files/70616684813.pdfIn PDF document text
    • http://www.greddy.com/admin/common/ckfinder/userfiles/File/92048326135.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/77282298007.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/mugorugu.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/dff3sf469djkjg75c137effbi9/56763744377.pdfIn PDF document text
    • https://doanandieuduong295doson.vn/namthuan/images/news/files/gomasoter.pdfIn PDF document text
    • https://instalacje-elektryczne.net/ckfinder/userfiles/files/pamudibexirebibiwuk.pdfIn PDF document text
    • http://rivucota.com/upload/files/zexisatep.pdfIn PDF document text
    • http://hotechike.com/files/files/23929613485.pdfIn PDF document text
    • http://angerdress.store/ckfinder/userfiles/files/83769801706.pdfIn PDF document text
    • http://studiogaleazzo.eu/userfiles/files/rigubapom.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/96264389139.pdfIn PDF document text
    • https://wrd13.com/force/file/22712338245.pdfIn PDF document text
    • https://ildiko-szepsegszalon.hu/userfiles/file/wilusekuzi.pdfIn PDF document text
    • http://omni-links-europe.com/images/blog/file/5183601209.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/tabaxivosuvor.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133c7fa63bc7---zolotakumikibujorif.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/33625026266.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131ddb857351---77102116630.pdfIn PDF document text
    • http://bsl-trans.ru/admin/ckfinder/userfiles/files/sowev.pdfIn PDF document text
    • http://ge-mak.com/files/24840865522.pdfIn PDF document text
    • https://sharjahcements.com/images/bulk_images/files/wopomonuwawada.pdfIn PDF document text
    • http://murzilka.biz/images/uploads/file/20255164704.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=vidmate+hack+mod+apk+downloadPDF 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_off0000c5d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dde8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDE8 10656 bytes
SHA-256: aed33355facf4cf6de676a4fc395e7ef0b9d9ebeba3d4a31de063c22c4c15abd
font_02_sfnt_off0000f625.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF625 17852 bytes
SHA-256: ff33a505573c47bdfd689a4c947e8123f62ef9469a7c0974a2558d4f61c71f44