Malicious PDF — malware analysis report

Static analysis result for SHA-256 d194f43bbe126499…

MALICIOUS

PDF

83.0 KB Created: 2021-09-18 14:44:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a9886c8e058af0943e1eaad95ecd90c4 SHA-1: 7864db9111a6d1eb63cb81eaf1f2b9e5b1107b99 SHA-256: d194f43bbe12649970039190673a2bb5968608526b531b03070527d9226893b8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Several heuristics indicate the PDF functions as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. While no scripts were directly extracted, the nature of the link farm suggests it is designed to redirect users to malicious content, likely phishing or malware distribution sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://www.tecnobor.com/ckfinder/userfiles/files/zuzodovisub.pdf In PDF document text
    • https://elsa-daulte.com/ckfinder/userfiles/files/xubikafudirutasixuwig.pdfIn PDF document text
    • http://viswinkelindex.nl/images/uploads/nolexekatezawomoxe.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/15a283b3393d962b88b4641723b914cb/51167446158.pdfIn PDF document text
    • http://smepil.com/ckeditor/userfiles/files/velifiwukefironefemujon.pdfIn PDF document text
    • http://studiotrusso.it/userfiles/files/83586822664.pdfIn PDF document text
    • http://oskarmak.com/userfiles/file/78110339975.pdfIn PDF document text
    • https://jmclimatizacionhvac.cl/images/subidas/file/55292950380.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/30546627475.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16136fb6fa3c47---fubodesikoxitezutinoneza.pdfIn PDF document text
    • https://areopag.ru/sites/default/files/uploads/pukuvilivobufafepulikikab.pdfIn PDF document text
    • http://satyavnetworks.com/fck_upload_images/file/15602898168.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/rugewatiditusadonuvu.pdfIn PDF document text
    • https://pastelbuilders.com/userfiles/file/42835086649.pdfIn PDF document text
    • https://cyberbirddog.com/userfiles/files/38125957791.pdfIn PDF document text
    • https://autoteam.in/ckfinder/userfiles/files/37446340206.pdfIn PDF document text
    • https://mylin.in/ckeditor/ckfinder/userfiles/files/32602954397.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/66612142103.pdfIn PDF document text
    • http://tindangnhadat.vn/upload/files/50181412455.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/dadf52884793633b659863d72be02036/36988981228.pdfIn PDF document text
    • http://www.neoneophytou.com/ckfinder/userfiles/files/27051518771.pdfIn PDF document text
    • http://sumosushingrill.com/uploads/files/fajoradefolixegelodoseji.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/6a5e8038bfeb4164cbcefa2c8dd480ee/ketalebaxizajosimofakeb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=usmle+step+1+2020+pdfPDF 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_off0000dbe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F6 19216 bytes
SHA-256: 8b706852f2257795d319c7aa72b58ebfd25a8d40b97f8efbb3a1de187c56b92f
font_02_sfnt_off000125d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125D6 10384 bytes
SHA-256: 88d6c1b024b7061ba98d8e16732fb5b0afc524eb145c85857f17990c6233349f