Malicious PDF — malware analysis report

Static analysis result for SHA-256 f90002031a14bbcb…

MALICIOUS

PDF

81.0 KB Created: 2021-09-12 19:57:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 864ec84edbc42fa2e7969b6f30cd3afd SHA-1: f4a0e40c0e162d64eef5e10dceec682a3fd8885a SHA-256: f90002031a14bbcb48ec4a8e4ab0fcb06d5fe106d70ae103bc9317db0367f7cf
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious, specifically as phishing-related. It contains a large number of embedded URLs, many pointing to disposable domains, indicating a link farm or phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a tactic to distribute malicious content or phish credentials. No scripts were extracted, but the primary attack vector appears to be directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=take+off+phrasal+verb+examples PDF link annotation
    • http://electric-kernbichler.at/pisemodalofukexe.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/vaxoxub.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/10384538311.pdfIn PDF document text
    • https://suprastoc.ro/userfiles/file/fupevijavanupitinepuv.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/21324204874.pdfIn PDF document text
    • https://khanikango.in/file/sorakesuwejiwe.pdfIn PDF document text
    • http://progettogeometra.it/userfiles/files/walepufebeposav.pdfIn PDF document text
    • http://crediramasrl.it/public/file/75944155082.pdfIn PDF document text
    • http://lse.hu/userfiles/file/86787598537.pdfIn PDF document text
    • https://www.adom.biz.pl/ckfinder/userfiles/files/sebosamimupexosewuj.pdfIn PDF document text
    • https://bestofbucerias.com/upload/file/dagewubiteni.pdfIn PDF document text
    • https://szallas-karpatalja.com/upload/mobunamosesini.pdfIn PDF document text
    • http://salt17.com/userfiles/files/daridinuvufobozozakowagot.pdfIn PDF document text
    • https://beruanglucu.com/contents/files/funarezebojulo.pdfIn PDF document text
    • https://raselapp.com/userfiles/file/nujadobopikufavufefi.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/60272971983.pdfIn PDF document text
    • http://charolais-hessen.de/write/userfiles/file/rakiwidifimamelav.pdfIn PDF document text
    • https://projectmine.hu/ckfinder/userfiles/files/venutinoreluz.pdfIn PDF document text
    • https://connatlas.com/home/conn/public_html/ckfinder/userfiles/files/malafutujepawufofibamigup.pdfIn PDF document text
    • http://ntvietnga.com/upload/files/9909550839.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b5e1a82679---bipatewemexumusug.pdfIn PDF document text
    • https://cukimentescukraszda.hu/files/files/tufig.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/buxiwusividevug.pdfIn PDF document text
    • http://koszyczarek.pl/userfiles/file/32971755955.pdfIn PDF document text
    • http://poongdung.com/FileData/ckfinder/files/20210902_023C3118E367D7E5.pdfIn PDF document text
    • http://boldino-hotel.com/ckfinder/userfiles/files/41838247490.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_off0000d6a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6A2 10692 bytes
SHA-256: 6fc27dd83f7cb1999878e6091a68f3aeee74650cc70cd4017921c2626a9673d0
font_01_sfnt_off0000ef07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF07 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010719.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10719 18124 bytes
SHA-256: 50366612a0ad98c427fb19823d492181bc6d2b8b9f63f152df1acc8ddb22e467