Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8b4af113f3c1356…

MALICIOUS

PDF

98.0 KB Created: 2021-08-11 04:47:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: ca30078e6dc2c82d30d06fa1d45400ff SHA-1: 48eb1035f766d53d0b143f6df56eabd5611b28db SHA-256: c8b4af113f3c135683d84ddcea1f0a57697a4ef97f4cb737a463734230cfb823
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting. While no scripts were explicitly extracted, the nature of link farms in PDFs often involves JavaScript to facilitate redirection, hence the inclusion of T1059.007. The primary attack vector is likely spearphishing attachment (T1566.001).

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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 https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a360e3f42b---96581894804.pdf In PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/6332a4d27a84b79c7e9d89ac1f04b0c2/tejidetow.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609df21cd0c17---90487752213.pdfIn PDF document text
    • http://cnzhongkui.com/fckeditor/editor/filemanager/connectors/php/uploads/file/300349593322.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/volemolamavixerunox.pdfIn PDF document text
    • http://macautemple.com/userfiles/file/vosazapoviratewakav.pdfIn PDF document text
    • https://barcelonacentremedic.cat/files/galeria/files/50652865975.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/4ohtoil2s2rcnsdiq82948rs1s/74125622307.pdfIn PDF document text
    • http://kronospan-mofa.hu/editor_up/juzamoxosubulaloji.pdfIn PDF document text
    • https://tepihtrava.rs//files/piwifipagapugemuj.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/6cd69b5db3b3747b7aed42dbfbe8083b/matafikegorijupisojepi.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/11035026356.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/gvsc8bkh53o3pu6m3pk892r508/7626596173.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/nuxujazesulafigatowaw.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160882a1ab2776---mozixiz.pdfIn PDF document text
    • https://matrainagycsalados.hu/userfiles/file/napezijiroj.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160835059a98b6---73095797301.pdfIn PDF document text
    • http://2018.letnifestiwal.pl/ckfinder/userfiles/files/1848614731.pdfIn PDF document text
    • http://simonide.org/userfiles/file/40052794306.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/e49b3db7479fec630333c39fa8963599/76129937088.pdfIn PDF document text
    • https://www.avantagesapp.com/uploads/files/56021496867.pdfIn PDF document text
    • http://wongkungfu.ca/clients/f/f5/f5c316b966f29b3192b3e9e3c5714b3c/File/jiwetu.pdfIn PDF document text
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/a6f901a3659dcfadcc50c4c177bf8d6d/73470507775.pdfIn PDF document text
    • http://haohanlegend.com/Uploadfiles/files/remeletutizeropa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=problemas+de+multiplicaci%C3%B3n+para+sexto+grado+de+primariaPDF 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_off00011247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11247 11336 bytes
SHA-256: 07f54d60dc8a2439f2269714ef99c949db415a3168b13cbfb1ce24f224801090
font_01_sfnt_off00012c45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C45 20124 bytes
SHA-256: d061af863d7a7d02d5d5dfa083470a90d84a3205f80e36a8675b6d24f380cae6
font_02_sfnt_off00015ee6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15EE6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1