Malicious PDF — malware analysis report

Static analysis result for SHA-256 c320add9af46a520…

MALICIOUS

PDF

84.1 KB Created: 2021-09-09 10:23:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7588f25a23a89ec3d4e6ca16ec7936b1 SHA-1: 50098cab283ddd182f2bca49c26b47b1bc90f23e SHA-256: c320add9af46a520f81bbb233f40ec112a21a8e71993335c04474b2d80df08db
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains a link farm with numerous URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://fceresources.com/ckfinder/userfiles/files/61326086866.pdf In PDF document text
    • http://isystemlab.com/admin/ckfinder/userfiles/files/gizalonujiguwebemesub.pdfIn PDF document text
    • http://union.travel/ckfinder/userfiles/files/gumisamotogolibulumep.pdfIn PDF document text
    • http://merklink.nl/site/data/ws/files/vujobaririfegumad.pdfIn PDF document text
    • https://digireg.at/upload/gemuxisulirorumupixo.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/161333273e7ac7---69622699277.pdfIn PDF document text
    • http://caycanh.vn/images/fck/file/fosesupinudu.pdfIn PDF document text
    • https://cmf8.ir/data/file/fozixukexepuvukasoju.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161361c9e01864---25148030234.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/ag345rjek2ldubdb45fbuhvam6/59103821449.pdfIn PDF document text
    • https://beta.nhatthiengroup.com/files/uploaded/files/sotorizurojugejunusi.pdfIn PDF document text
    • https://lucky-erotic-massage-bucharest.ro/ckfinder/userfiles/files/41290107663.pdfIn PDF document text
    • http://888chji.com/userfiles/files/zodipodurofaxex.pdfIn PDF document text
    • http://sattosushi.com/uploads/files/46751515912.pdfIn PDF document text
    • https://ekransamara.ru/files/jeturidewuna.pdfIn PDF document text
    • http://condominiobrisasdelnorte.com/userfiles/file/63907599122.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/c8a0b5e2c56c35e341b1c20854316bc4/78281017838.pdfIn PDF document text
    • https://skvacations.com/userfiles/file/87454174657.pdfIn PDF document text
    • http://trlgpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/52108013449.pdfIn PDF document text
    • http://grgct.com/ckfinder/userfiles/files/64002883394.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/fesuvofeserite.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132197300ce2---44774640920.pdfIn PDF document text
    • https://woft-dining.com/webroot/editor-uploads/files/xumatawegapemed.pdfIn PDF document text
    • http://uniquecharacters.com/upload/files/rafoxumo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=mini+militia+pro+pack+free+downloadPDF 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_off0000e43c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE43C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC53 10784 bytes
SHA-256: 825ab8a5c66603c415694165cdfe3637bd49ba01e0df9e7b9230f2e2fe847257
font_02_sfnt_off00011524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11524 17672 bytes
SHA-256: 8f5058bd9728d929fda7ecac891932a7ec4b7b9f6f353e4c4bfab525e4356c29