Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1558aa77f6bc591…

MALICIOUS

PDF

67.9 KB Created: 2021-09-25 02:06:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a91191414135f469cd6945767c5937e5 SHA-1: f5ce1659b97e37f0ae087c4b33ca77f513f26bb8 SHA-256: b1558aa77f6bc5914edb0ea6f358862d666f5572f39a5fabbe56b20fb414c23a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. While no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript to facilitate redirection, hence the inclusion of T1059.007.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/h3cv3r6th18lohteg7ld1r5uh7/nuremakifofeza.pdf In PDF document text
    • https://makanbanyak.net/contents/files/91173219446.pdfIn PDF document text
    • http://tunecharts.com/userfiles/file/19885406646.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/tuxaje.pdfIn PDF document text
    • https://408of53crownstreet.com/assets/media/files/15356606798.pdfIn PDF document text
    • http://santinitravel.co/files/others/70462983541.pdfIn PDF document text
    • http://gioiacompany.net/images/upload/file/gezedarijezikuzaw.pdfIn PDF document text
    • http://uticachemical.com/files/upload/files/64773875475.pdfIn PDF document text
    • http://cana.vn/uploads/userfiles/file/9884773150.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/4433992155.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/ptc9t2b873djocm4v304gfqkf4/75074127123.pdfIn PDF document text
    • https://bnovum.hu/downloads/87562578917.pdfIn PDF document text
    • https://s-serviss.lv/userfiles/file/kekekafupilusoseduduga.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/37304442239.pdfIn PDF document text
    • https://pasarantogel2.com/contents/files/55945178846.pdfIn PDF document text
    • http://ricoconsultingattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fivitiv.pdfIn PDF document text
    • http://4226080.kad.tw/kads/ckfinder/userfiles/files/lodomikolizijewopajotu.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/d7fe06ec986ec7b180bb7e989b934c7e/58716030837.pdfIn PDF document text
    • http://mfo-fond.ru/ckeditor/ckfinder/userfiles/Images/files/52877218990.pdfIn PDF document text
    • https://shoppingplanet.ro/ckfinder/userfiles/files/37020378731.pdfIn PDF document text
    • http://tykhchem.com/upload/files/xokazatowuvukakobelo.pdfIn PDF document text
    • http://energosol.pl/images_cms/file/xuvoxivugofimozalat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=sweet+valley+high+watch+onlinePDF 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_off0000ad30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD30 10584 bytes
SHA-256: 2b41f14234351a5d3195f303e1f168fc91ee6dd7cd8dedff37eec0f8a44f90c5
font_01_sfnt_off0000c56d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC56D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000dd7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7F 14708 bytes
SHA-256: 02750aa62970abfd7c3ec4ea5b380d1f85b7bc0782aac79b0bbae1a9edbf23f0