Malicious PDF — malware analysis report

Static analysis result for SHA-256 3df9e36dede84d43…

MALICIOUS

PDF

92.8 KB Created: 2021-09-13 18:35:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ea2fb857437f65a4fea46e59a6b3a6a5 SHA-1: fcdd05fd424eb99828fd055671456f5b6fa5f32c SHA-256: 3df9e36dede84d4310e45251b98a1eb977793e1452dd9a2e48fe6cf8a7f51837
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and link farm heuristics, indicating its primary purpose is to redirect users to other sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The presence of compromised CMS upload links further supports a malicious distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://synerhu.ru/uplcv?utm_term=indian+idol+junior+winner+2019 PDF link annotation
    • http://dr-onesrl.com/userfiles/files/40187977400.pdfIn PDF document text
    • http://commissioncollectionlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rugemesubanorulev.pdfIn PDF document text
    • http://sdhmladavozice.cz/userfiles/file/vebojomedamupomo.pdfIn PDF document text
    • http://lonniestireandauto.com/nbloom/fckuploads/file/99124695409.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/85mbj2ued9jlslg9usm4u0ok1k/gegarux.pdfIn PDF document text
    • http://elma-itc.ru/!upload/files/55491961358.pdfIn PDF document text
    • http://tnslib.net/userfiles/files/76666961791.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/99256935896.pdfIn PDF document text
    • http://dawahcity.com/userfiles/file/28477996192.pdfIn PDF document text
    • http://edituj.cz/res/file/4166688645.pdfIn PDF document text
    • http://dakmoto.cz/obrazky/file/sikufapekusi.pdfIn PDF document text
    • https://motoralbini.it/files/file/57643632629.pdfIn PDF document text
    • https://chambredhotes-savoie.com/ckfinder/userfiles/files/selugedisozesetulogowed.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/novefavuxa.pdfIn PDF document text
    • https://efficientinfocomm.com/ckfinder/userfiles/files/sulolosasuz.pdfIn PDF document text
    • http://nature-revive.org/files/file/64887912782.pdfIn PDF document text
    • https://sanagustin.cl/files/vimesikuwisujinajivanukav.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161368377d1a36---25718947858.pdfIn PDF document text
    • https://teater77.nl/userfiles/file/50944044629.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/161332cc721805---gufis.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/vedunabelogi.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/dawuwadod.pdfIn PDF document text
    • http://leaders-adv.net/userfiles/file/legexulo.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_off00010592.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10592 10704 bytes
SHA-256: 2484cc8a8472a4e2a5a0fab9787a51bdab431de23da8d035a262e130b1685568
font_01_sfnt_off00011e4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001365e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1365E 18332 bytes
SHA-256: 66475df5eba9aa01db26a7519fba0320ebf9a374d3ab4c74fe28f3a9a87dccfc