Malicious PDF — malware analysis report

Static analysis result for SHA-256 a332ede4b82a8616…

MALICIOUS

PDF

85.1 KB Created: 2021-09-18 23:25:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8cecef1347dd721cfb36d16644007c13 SHA-1: 55174f37d72ce110bd33e615ef9e85f2d9adee63 SHA-256: a332ede4b82a861656afb542f37fff770765349a497af1de272bd73972eff775
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to user-uploaded content on compromised websites, suggesting a link farm or SEO poisoning tactic. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://ventss.ru/userfiles/files/migesexuwidibe.pdf In PDF document text
    • http://innotack.com/userfiles/files/98319156654.pdfIn PDF document text
    • http://schokoladenbrunnen.de/idata/94039363416.pdfIn PDF document text
    • http://centromp.it/userfiles/files/96703610298.pdfIn PDF document text
    • http://owop.challengersports.com/ckfinder/userfiles/files/rogixemosol.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/86241944678.pdfIn PDF document text
    • https://zlato-stribro-investice.com/upload/files/59317671772.pdfIn PDF document text
    • http://gemwishrs.com/ckfinder/stones/files/witifulukuperinivi.pdfIn PDF document text
    • https://kristinanamaste.eu/files/gazejip.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161445a22e7f4a---limiku.pdfIn PDF document text
    • http://4reality.cz/userfiles/files/gesujiloramisav.pdfIn PDF document text
    • https://groupunsur3.com/contents/files/9335696212.pdfIn PDF document text
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/57948993112.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/45b80e83411c5fbb460471db7946f862/49726961314.pdfIn PDF document text
    • https://hetodon.com/fckeditorfiles/file/sediviketibaf.pdfIn PDF document text
    • http://graviroz.hu/ckfinder/userfiles/files/tixomixabipi.pdfIn PDF document text
    • https://dolupin.com/calisma2/files/uploads/69191497821.pdfIn PDF document text
    • http://arredamenticucinesiciliane.it/userfiles/files/88235048236.pdfIn PDF document text
    • http://proclima-membranes.ru/userfiles/file/turelubipezidoroso.pdfIn PDF document text
    • https://www.gico.ge/ckfinder/userfiles/files/12025242011.pdfIn PDF document text
    • http://giasudaihocsupham.com/Images_upload/files/20734421502.pdfIn PDF document text
    • http://hoachattn.com/image/files/68912775593.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/161312bebe6b84---xuwiretazerejubinox.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/161369381429b3---74344963153.pdfIn PDF document text
    • http://falconartistmanagement.com/ckfinder/userfiles/files/fobuz.pdfIn PDF document text
    • https://olterus.info/contents/files/gefom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=arrow+sign+copy+and+pastePDF 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_off0000dbf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF2 21900 bytes
SHA-256: 596c6bb6256cc14be49779866b7b923733068ad67a20f7f988c329f77e24fca6
font_01_sfnt_off0001157c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1157C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012d93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D93 10824 bytes
SHA-256: afa0838cbd27931e3a86d01a6e8aa3b9c41717be9a1e088bd9ee1a373c71b41c