Malicious PDF — malware analysis report

Static analysis result for SHA-256 11357f62e57dc840…

MALICIOUS

PDF

68.4 KB Created: 2021-10-02 11:46:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c5d7b62724fb4c23de086abe7b06b0dc SHA-1: 9624cbf1e8f7ca5a15c3ef5fd83e8df5d2d42e08 SHA-256: 11357f62e57dc84083355fd54ad1b850b3fbb4a556f27d1f0c769664f0739452
126 Risk Score

Malware Insights

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

The PDF sample was flagged by ClamAV and an ML classifier as malicious, indicating it likely contains malicious content. Heuristic analysis revealed it functions as a link farm, with numerous embedded URLs pointing to disposable hosting and redirectors, suggesting a phishing or malware distribution scheme. The presence of multiple external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://laborke.ru/uplcv?utm_term=forked+palm+lines PDF link annotation
    • http://speckletrack.com/update/editor/file/jeripakepomew.pdfIn PDF document text
    • https://birotex.rs/images/files/41874825161.pdfIn PDF document text
    • https://cafemocion.com/userfiles/file/mugulovasix.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16142901201ab1---33491090271.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/1fdojhho6fhubhhc4oe5ldqm23/30877309477.pdfIn PDF document text
    • http://henzefashion.com/userfiles/file/24587020797.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/wosirojujusavi.pdfIn PDF document text
    • http://unixsensor.com/uploads/files/202109230351571314.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/4136515660.pdfIn PDF document text
    • https://speeddating.lt/speeddating/ckfinder/userfiles/files/71708164669.pdfIn PDF document text
    • https://peltonfell.org.uk/ckfinder/userfiles/files/25209720541.pdfIn PDF document text
    • http://archive-2014.humandoc.pl/attachments/file/winidovunisikujomimoxef.pdfIn PDF document text
    • https://materiale-parchet.ro/fisiere/file/sugobuludawixatanoxo.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/37916243322.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/nifopuloxeloxosek.pdfIn PDF document text
    • https://thaiwoodengames.com/files/upload/files/38886018206.pdfIn PDF document text
    • http://seoaudytor.pl/userfiles/file/gadarukenipofutolixali.pdfIn PDF document text
    • http://cnsgawefgl.netsociality.com/upload/files/99302955885.pdfIn PDF document text
    • https://betsin.org/userfiles/files/pazakuxadixiwa.pdfIn PDF document text
    • https://hamzakocakoglu.com/userfiles/file/barebojubolibugon.pdfIn PDF document text
    • https://xosobacninh.vn/webroot/img/files/duzumasakuvodasugubu.pdfIn PDF document text
    • http://orsini-blasioli.it/userfiles/files/8799383822.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_off0000aefa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEFA 10524 bytes
SHA-256: f3291bdf8e00bf22da14e17f30ae7b056f477dd9a89699331127e5d2c28a6f84
font_01_sfnt_off0000c6cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6CF 15000 bytes
SHA-256: 6ec6347672ce48ef4ab2c995056a136e7335ae24e2588f19d37cb40c68d08b2f
font_02_sfnt_off0000ec28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC28 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1