Malicious PDF — malware analysis report

Static analysis result for SHA-256 b606fc0aa7db74fa…

MALICIOUS

PDF

74.1 KB Created: 2021-09-12 09:58:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: dcb7a5f30ac1d35f787c3f2f43eb7f39 SHA-1: cd805e345eca3bb1500e28becd1ce4f84b21eb6d SHA-256: b606fc0aa7db74fa711364ea5f2bd619828eab853718ef77afd3d7158149ad57
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous embedded URLs, many pointing to disposable hosting and utilizing UTM parameters, strongly suggests a phishing or malware distribution campaign. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically highlights the link farm nature of the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://queure.ru/uplcv?utm_term=increase+bluetooth+volume+android PDF link annotation
    • https://dusunceokulu.net/resimler/files/1778504877.pdfIn PDF document text
    • https://bellcera.60km.com/upload/files/dadusikemamafiwamataxot.pdfIn PDF document text
    • http://www.drivingschool-brno.cz/files/files/55351798295.pdfIn PDF document text
    • https://ms2gacor.com/contents/files/93934519154.pdfIn PDF document text
    • https://duvanco.be/docs/files/feronabafozoditat.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/37607572326.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/files/kelubix.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/41esgepqkm87upjvnu7ptsousr/xorosavuw.pdfIn PDF document text
    • http://businessdevelopmentcenter.pl/uploads/userfiles/files/92935114274.pdfIn PDF document text
    • https://cortopolis.ar/userfiles/file/45914637655.pdfIn PDF document text
    • https://escolaalfa.com/userfiles/file/78799558136.pdfIn PDF document text
    • http://telesson.net/_UploadFile/Images/file/14962737943.pdfIn PDF document text
    • http://medrea.ru/upload/files/12314009314.pdfIn PDF document text
    • http://ibarugi.com/fckeditor/userfiles/file/topopozisajoz.pdfIn PDF document text
    • https://openkomm.yussfone-crm.com/userfiles/file/zerefadiju.pdfIn PDF document text
    • https://inprovit.com/ckfinder/userfiles/files/99119538484.pdfIn PDF document text
    • http://vankouwenenmastop.nl/UserFiles/file/tipanifajilerutinax.pdfIn PDF document text
    • https://amgaa.org/temp/files/tubexafezepuxeji.pdfIn PDF document text
    • http://meyergarden.com/ckfinder/userfiles/files/kezowovurenuwakexaxu.pdfIn PDF document text
    • http://glavis.biz/userfiles/file/dunelazite.pdfIn PDF document text
    • https://posetili.ru/userfiles/file/zimitijiw.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/2021951145411727.pdfIn PDF document text
    • http://www.recko.ru/ckfinder/userfiles/files/masifekuvilifubujukin.pdfIn PDF document text
    • http://www.octopus-quatuorvocal.com/ckfinder/userfiles/files/77323108064.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_off0000bf79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF79 10892 bytes
SHA-256: cdec0be0a9031cbe9e752b063140aa5637bec31a08a06462a09a5daa253567b2
font_01_sfnt_off0000d874.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD874 16480 bytes
SHA-256: 3ca17278c716df949922b61c2707ac450a6b8a5e7977e356cec922c8ead9cf2e
font_02_sfnt_off000102ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1