Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7c6c96dc5c92d73…

MALICIOUS

PDF

101.1 KB Created: 2021-09-12 17:38:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a33f41911d74988de0819c7f5452016b SHA-1: 7e1d0bce84c1b2e55656a54cda04f057f225f2b0 SHA-256: b7c6c96dc5c92d73e405e094fadd979942febc94e82457b4635e6c57caaa1eec
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and is flagged as a link farm on disposable hosting, suggesting a phishing or malware distribution lure. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used for initial access via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9931

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://medvor.ru/uplcv?utm_term=what+is+a+diagraph PDF link annotation
    • https://toptenstudy.com/upload/files/BodyFile__613AF8FE514E7.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d9814f20bb---kaguzu.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/dagalemonijazure.pdfIn PDF document text
    • http://federicozucchettiarchitetto.eu/userfiles/files/rubinefiganan.pdfIn PDF document text
    • http://allgeology.ru/ckfinder/userfiles/files/3951661003.pdfIn PDF document text
    • http://harlit.com/ckfinder/userfiles/files/20210911_145146.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/wuvuvi.pdfIn PDF document text
    • http://skidubravy.sk/spravca/ckfinder/userfiles/files/kusokefukawivatanisada.pdfIn PDF document text
    • http://yjeverspeed.com/userfiles/file/moluwazenibilikebasemu.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/xinusebebiwisitufod.pdfIn PDF document text
    • http://www.espace-hotelier.com/ckfinder/userfiles/files/19679094519.pdfIn PDF document text
    • https://totalmediasolutions.ae/ckfinder/userfiles/files/24679834253.pdfIn PDF document text
    • https://venusnvs.com/userfiles/file/5272248805.pdfIn PDF document text
    • http://bloomx.com/sites/all/sites/bloomx.com/files/dukoruserakajadikivogiwu.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/517925746.pdfIn PDF document text
    • http://studiobaldizzone.com/userfiles/files/digiwebovaf.pdfIn PDF document text
    • http://polipack.ru/content/file/34373866361.pdfIn PDF document text
    • http://potlista.com/file/files/risokax.pdfIn PDF document text
    • http://vinag7furniture.com/app/webroot/files/editor_upload/files/89116969906.pdfIn PDF document text
    • http://www.trisad.kz/ckfinder/userfiles/files/xoreruw.pdfIn PDF document text
    • http://xn--q20b13r9leepaeb.net/upload/file/202109030351346130.pdfIn PDF document text
    • http://fermobkorea.com/userfiles/file/20210901073708.pdfIn PDF document text
    • http://www.stadion-zarya.ru/ckfinder/userfiles/files/8383542119.pdfIn PDF document text
    • http://velapower.com/glwh/UploadFile/file/2021090404483273499.pdfIn PDF document text
    • http://www.bluefashion.cz/ckfinder/userfiles/files/40804565864.pdfIn PDF document text
    • https://cafepiolho.com/uploads/assets/46691227799.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_off00011c13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C13 22356 bytes
SHA-256: 8e750558469ee8b34269f00dac427fcd13be00c2262f47f6ce9322ef7bc20026
font_01_sfnt_off000156f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x156F2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016f09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16F09 10264 bytes
SHA-256: 8d6059f133ebc4e0751671ad75fe2455b95a21614ecb811a7074ea5213a2f283