Malicious PDF — malware analysis report

Static analysis result for SHA-256 128750caf4e42061…

MALICIOUS

PDF

80.8 KB Created: 2021-09-18 23:02:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d730a553a766f68167bc646f2714dd3e SHA-1: ec2fd8cc2ed793923538e2a27947a5ed738f4be1 SHA-256: 128750caf4e420610facf5dcff454bf83bcbbddc96e2d16db19f60623908cb7a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, suggesting it's designed to redirect users to potentially harmful websites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the idea that the PDF is part of a link farm, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://crewmak.ru/uplcv?utm_term=algebra+2+completing+the+square+worksheet PDF link annotation
    • http://yonezawanet.jp/units/24250/zcycom/files/35329530179.pdfIn PDF document text
    • http://villabrown.it/userfiles/files/98444334087.pdfIn PDF document text
    • http://venkateshservices.com/uploads/46929293806.pdfIn PDF document text
    • http://foodchemsino.com/d/files/rapezuwuxunugarutu.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/teketexokozogobopoxokiki.pdfIn PDF document text
    • http://eldmsh1.ru/js/ckfinder/userfiles/files/84683395941.pdfIn PDF document text
    • http://azseal.net/uploads/userfiles/file/47226487251.pdfIn PDF document text
    • http://doktor-okonski.pl/uploadimg/file/pexikelukapogumizig.pdfIn PDF document text
    • http://paitoonbox.com/userfiles/files/vabulewolijinoper.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/sixemumifuralojulozenape.pdfIn PDF document text
    • http://prosefkuchare.cz/userfiles/79324648560.pdfIn PDF document text
    • https://maggievanostrand.com/uploads/media/file/femewafaluken.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1613b05ee7aeac---sopamemejivubepo.pdfIn PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/31390908976.pdfIn PDF document text
    • https://equimat-cheval.fr/file/21695963446.pdfIn PDF document text
    • http://consorzio-csa.it/userfiles/files/zedip.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/22840292046.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b804210c0a---mawoxixedenizowewiniwiku.pdfIn PDF document text
    • http://www.fan-consultants.com.tw/ezadmin/ckfinder/userfiles/files/giramu.pdfIn PDF document text
    • https://khachsan295doson.vn/namthuan/images/news/files/12776432121.pdfIn PDF document text
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/60837180051.pdfIn PDF document text
    • http://shop-exclusive.cz/userfiles/file/76032980526.pdfIn PDF document text
    • http://udelimpa.es/ckfinder/userfiles/files/95526861583.pdfIn PDF document text
    • http://kwartetproforma.com/userfiles/file/muluditobuwepaginurarevet.pdfIn PDF document text
    • http://arserwood.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210911025409893151akxtgw.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_off0000d31a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD31A 18248 bytes
SHA-256: 9ed9f41565ffea0d921a542f9755adda852825ad8611eefc0762791925a52800
font_01_sfnt_off000102c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C6 11484 bytes
SHA-256: b5eb97858c2e8d8febcc9e2a7f9b80803e08b7ec7867ed46cd0b21fbed914025
font_02_sfnt_off00011d66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D66 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1