Malicious PDF — malware analysis report

Static analysis result for SHA-256 399d0c9665da98c2…

MALICIOUS

PDF

85.8 KB Created: 2021-09-18 15:04:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 863671a925a445110e071857aec65f8f SHA-1: ca34261ec8014b602d4c6e582832fa9e546c2115 SHA-256: 399d0c9665da98c2072cd9fbcb89bfaf70c64f91c72ba42a1ea9751f46cd43f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The document body is unreadable, suggesting it may be obfuscated or contain only structural elements. The primary attack pattern involves luring users to click on these links, potentially leading to further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://vico-real-estate.com/ckfinder/userfiles/files/49769126136.pdf In PDF document text
    • http://manpukulivermore.com/uploads/files/68515085029.pdfIn PDF document text
    • http://boek.se/bilder_umeny/File/90251241558.pdfIn PDF document text
    • http://xedaptheduc.net/app/webroot/uploads/files/76457954691.pdfIn PDF document text
    • https://www.eos.org.eg/ckfinder/userfiles/files/73940137970.pdfIn PDF document text
    • http://msiutilities.biz/documents/gedirosizijuti.pdfIn PDF document text
    • https://suma.ca/upload/editor/file/46165415142.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16133a4a1266e8---48438022729.pdfIn PDF document text
    • http://levotst.com/uploads/files/93687303446.pdfIn PDF document text
    • http://fst-uinsu.net/userfiles/files/75071897755.pdfIn PDF document text
    • https://afayl.com/userfiles/file/zevigupifosef.pdfIn PDF document text
    • https://vatlieutaphu.com/upload/files/19284693011.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613746bf1990f---50508297785.pdfIn PDF document text
    • http://ideatity.com/ckfinder/userfiles/files/rikarur.pdfIn PDF document text
    • http://bluestandard.pl/ckfinder/userfiles/files/46836878587.pdfIn PDF document text
    • http://www.sname.org.tw/sname/ckfinder/userfiles/files/bonutuvudewufipobiluvu.pdfIn PDF document text
    • https://eminenceconstruction.ca/viking1/uploads/files/vuxetolu.pdfIn PDF document text
    • http://mos-craciun-inchiriere.ro/fckfiles/file/banoxoramepube.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135174881f79---suwixetuzovabaki.pdfIn PDF document text
    • http://xn--80aafkatcapceshpicpg3h.xn--p1ai/pict/file/31716094818.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/332f4aab592e5ddafd864a1a4f3d7000/47948361209.pdfIn PDF document text
    • http://domuran.pl/files/file/vubeturuxiximajajeduladov.pdfIn PDF document text
    • https://karapinler.com/calisma2/files/uploads/duvipipitagugusikedazipew.pdfIn PDF document text
    • http://holdemigny.fr/ckfinder/userfiles/files/72654946191.pdfIn PDF document text
    • http://klwas.org/userfiles/images/file/tijiwemozejaxurajumama.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=brooklyn+99+season+1+putlockerPDF 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_off0000e82e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE82E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010045.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10045 10856 bytes
SHA-256: e7e1aab439f27e459f3fd6f1ddb15c402e417f3b2db0ccf6dace941c81c8f6eb
font_02_sfnt_off000119a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119A5 18436 bytes
SHA-256: d89bf655f771055e145fbb4662d71e0fc45906ead6c7d5c787219250f5a563f5