Malicious PDF — malware analysis report

Static analysis result for SHA-256 816bd228b9661447…

MALICIOUS

PDF

86.6 KB Created: 2021-09-18 00:47:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 67119ca9a0ac902a243a7c97b1a38aae SHA-1: e44214b3c98593f4e7777586a531c27ea212dc32 SHA-256: 816bd228b9661447aabb52ee744e75a76b3e9f0bfa657f86f8db5970ea92ff13
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ClamAV and an ML classifier. It contains a large number of embedded links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a deliberate effort to obscure the final destination and potentially evade detection. No scripts were extracted, but the overall structure points to a malicious document delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://queure.ru/uplcv?utm_term=key+features+of+android+operating+system PDF link annotation
    • https://taxfirma.com/userfiles/file/91243839779.pdfIn PDF document text
    • https://kingwaterpure.com/ckfinder/userfiles/files/30223841415.pdfIn PDF document text
    • http://studioschicchi.eu/userfiles/files/latajevibuxenapez.pdfIn PDF document text
    • http://wordtmann.beckbauer.eu/ckfinder/userfiles/files/66689444409.pdfIn PDF document text
    • https://jin-ji.com/upload/files/55367693177.pdfIn PDF document text
    • http://imssp.by/data/images/fxeditor/file/99104964574.pdfIn PDF document text
    • https://onderdurdu.com/upload/ckfinder/files/26766525303.pdfIn PDF document text
    • https://7mark3t2-7aya.com/contents/files/2628109173.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/vepifosotigura.pdfIn PDF document text
    • https://jjpremiers.com/files/gujupaxobolil.pdfIn PDF document text
    • http://conomiya.com/images/uploadedimages/file/wizefuzibudeloxibobozika.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/313sep7qti6qc5hbte3j5b6jp4/5769623021.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/fgegn1ci1q1ug264agb6hs0vvt/xumuwujatinuripikozubixo.pdfIn PDF document text
    • https://editionsitaliques.com/userfiles/file/miwowutefelur.pdfIn PDF document text
    • https://www.pactforfamilies.org/ckfinder/userfiles/files/92373046084.pdfIn PDF document text
    • https://santa.my/images/users/00000000/files/45453386820.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613478debe647---25842719677.pdfIn PDF document text
    • http://fantalife.nl/userfiles/file/25573440222.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/8bf95aa639ccf98b24cbcdf5a04d1746/15803739395.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210908_F84C921810A54913.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/09052651258.pdfIn PDF document text
    • http://fields-on-earth.com/images/blog/file/8802835647.pdfIn PDF document text
    • http://detectiveoffice.net/userfiles/file/lenabumopubazonefujakuv.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/21313432757.pdfIn PDF document text
    • https://korvioinfotech.com/ckfinder/userfiles/files/filunujofegafoso.pdfIn PDF document text
    • http://studioego.cz/userfiles/file/12356365510.pdfIn PDF document text
    • 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_off0000ebf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF7 18252 bytes
SHA-256: bd81e6309b0dd4a01030451b20a528deeaf159f2459576c4a3d5046d3a6f13fc
font_01_sfnt_off00011b54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B54 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001336b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1336B 11000 bytes
SHA-256: 5b77f9fcea51a4f34322282631fc61e134e78c6fcb2e1e6f2ed2b0ef2df0f94d

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