Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc398a10dc6079b9…

MALICIOUS

PDF

92.2 KB Created: 2021-07-07 00:09:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c844fac48730f988ca86faad9cfe3e4f SHA-1: 2caa633ceb2c4a8b50ba691315c11c21e9dc6adf SHA-256: dc398a10dc6079b9cd95f02b08f8e5b794ce16584dca01a4c581deeb885229fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://htapigroup3.com/contents//files/4793507395.pdf In PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/t6vcj0vh0v4ncc8vi5dvimtp50/66505755242.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/39288457221.pdfIn PDF document text
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/julologajojogabog.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/060208189169.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607cdaace2fbb---xozepi.pdfIn PDF document text
    • http://flex-link.cn/uploadfiles/files/zezadekovifog.pdfIn PDF document text
    • http://klefmarken.se/upload/file/vivaxorevebu.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1607d57470d300---lifefasabu.pdfIn PDF document text
    • http://wang023spa.com/userfiles/202107file/2021070205084470554.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607caf6447cf3---bikivuxilunovare.pdfIn PDF document text
    • http://thicongdiennuocmiennam.com/uploads/files/limewu.pdfIn PDF document text
    • http://boracayg.com/FileData/ckfinder/files/20210706_5727A0A55B424E2E.pdfIn PDF document text
    • http://boilerservis.ru/uploads/files/32143506443.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/guzavizomojulekozebumetu.pdfIn PDF document text
    • https://decoveinvestment.com/userfiles/file/83424013423.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16098a8135dec5---vexekewilem.pdfIn PDF document text
    • http://eraucheta.ru/uploads/file/fegan.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/c9dkau1j3tukdu2c3take8t0cl/difuzalufijifasedanomiseb.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/ji6h0emhglf6hlgak2olorfdoq/sovix.pdfIn PDF document text
    • https://medtek.vn/storage/file/megumedinomipurixirofimu.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/ab4f837c76d3ac2cc8327895c517e008/99597599809.pdfIn PDF document text
    • http://haniltm.kr/upfiles/editor/files/16117277294.pdfIn PDF document text
    • http://innova-perila.ru/upload/files/pufusujepo.pdfIn PDF document text
    • http://podlahyadvere.sk/editor_uploads/system/files/37201606496.pdfIn PDF document text
    • http://kingcraftviet.com/uploads/ckfinder/files/livudute.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=sample+request+letter+to+purchase+an+item+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_off000103cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103CB 11208 bytes
SHA-256: 5416348526e85f6e3750ef55f9b2a9c5c625988d0cdca204e8a9182eb6d5d07d
font_01_sfnt_off00011d8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D8A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001359c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1359C 17420 bytes
SHA-256: 6a6eb62bd70a6d904771a5f385a5f20fb783a7365b2db4ad8d2b5520571b255e