Malicious PDF — malware analysis report

Static analysis result for SHA-256 b714049e5fd9e867…

MALICIOUS

PDF

83.1 KB Created: 2021-09-08 21:26:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4057a66ded0c2356735a8b3d3d80ba7b SHA-1: c4c7790a4963c7cc4c30290a3d9acac39aa90be8 SHA-256: b714049e5fd9e8671fe333aeae70ab15fde93c7fe81571b7abdcb3dce5f4c5e2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to other PDF files, many hosted on disposable or low-reputation domains, indicating a link farm or redirection scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these linked documents. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9780

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://cructi.ru/uplcv?utm_term=a+programmer%27s+introduction+to+mathematics+pdf%E4%B8%8B%E8%BD%BD PDF link annotation
    • http://m3hotels.com/userfiles/file/mitazawisigot.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/25005976428.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/zadorujotixenan.pdfIn PDF document text
    • https://szallas-karpatalja.hu/upload/95841225433.pdfIn PDF document text
    • http://htygroup.com/upload/files/deravitosuwulesu.pdfIn PDF document text
    • http://leeandrewdavison.com/download/zarogaxoloza.pdfIn PDF document text
    • http://mimarkamilozkartal.com/userfiles/files/715003646.pdfIn PDF document text
    • https://voziky-paletove.cz/mctree.cz/pictures/other/files/60381523117.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/gavan.pdfIn PDF document text
    • http://cpghollywood.com/userfiles/files/2167972100.pdfIn PDF document text
    • http://vdavloeren.be/userfiles/files/18729739176.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/3c7f8e99d7c41a57e86579632a58f337/fufojizimu.pdfIn PDF document text
    • http://clingac.es/d/files/67679045067.pdfIn PDF document text
    • http://a2hgghk.handylover.com/upload/files/wisagetobovixijorap.pdfIn PDF document text
    • http://seanmore.com/userData/board/file/38981679140.pdfIn PDF document text
    • http://kite-surf.sk/files/51318189143.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/82113667196.pdfIn PDF document text
    • http://z500.si/files/gedav.pdfIn PDF document text
    • https://estduquebec.com/scripts/php/xenocode/lib/ckfinder/userfiles/files/nujidox.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/ruxupu.pdfIn PDF document text
    • https://kop-trans.pl/uploads/userfiles/files/66773875302.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/bepiwugowi.pdfIn PDF document text
    • http://babyindex.nl/images/uploads/82352766416.pdfIn PDF document text
    • https://dichvumoinoi.com/ckfinder/userfiles/files/jajelusujixozupu.pdfIn PDF document text
    • https://texigo.tw/upfile/files/2021/09/03/45508438105.pdfIn PDF document text
    • http://cathugo-catamarans.de/res/wysiwyg/file/kinubejabos.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cfba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFBA 1948 bytes
SHA-256: b033f7fcbcd390b2cb396fbb5f03ef01f7ca9afc151f9d9df21604321f961cfa
font_01_sfnt_off0000d8bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f0d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D4 11136 bytes
SHA-256: 7985a44567fc548cc4195ba4a2a9a2d8a32080699eedc1bd59ecc3e4efae15b2
font_03_sfnt_off00010a86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A86 18696 bytes
SHA-256: 008261ecd61058899c26a628982984247c5fbb6536c52e7124e83a8d8bf2934e