Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c85b13d8c84015f…

MALICIOUS

PDF

87.6 KB Created: 2021-09-17 07:21:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0e1b2dc43517aa1c14acc3caf0c73704 SHA-1: e481dda757fc65eba701b022c8198520b29446e1 SHA-256: 9c85b13d8c84015f9b3b4fd0e2e83b280187c1cd538206b3f8e40362b4a8e535
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable domains, and a heuristic identified it as a link farm. ClamAV detected it as Pdf.Phishing.Trojan, and an ML classifier also flagged it as malicious. The primary attack pattern appears to be SEO manipulation or a phishing lure, leveraging a large number of links to potentially distribute malicious content or improve search rankings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://www.sec-ollivier-associes.fr/www/upload/file/fujodanuwefijilowogax.pdf In PDF document text
    • http://stjconsulting.it/userfiles/files/92228239529.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f559fc02b2---xegodexodubudawan.pdfIn PDF document text
    • http://bookblog.kr/data/file/files/jovojivomagurovopozalufib.pdfIn PDF document text
    • http://www.samuitns.com/image/upload/File/matujejazoxunite.pdfIn PDF document text
    • https://nieruchomosciprzetargi.pl/files/file/5761097451.pdfIn PDF document text
    • https://mimpiindah168.com/contents/files/teporazebugowibur.pdfIn PDF document text
    • http://umffz21.ru/admin/ckfinder/userfiles/files/rutatupudutakoruses.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/kudavodapokerus.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/28824645775.pdfIn PDF document text
    • http://concilianavarra.com/userfiles/files/zonezovuvuravonokub.pdfIn PDF document text
    • http://agro-pasz.pl/ckfinder/userfiles/files/gerufisiminuguninakuzo.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/mowoteg.pdfIn PDF document text
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/32558401605.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/5092640544.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/29640237689.pdfIn PDF document text
    • http://elijasprojekts.lv/files/file/72008929939.pdfIn PDF document text
    • https://cortopolis.ar/userfiles/file/96938935626.pdfIn PDF document text
    • http://lammermoor.net/imagenes/file/lezobegimidujuruzides.pdfIn PDF document text
    • http://sbriz.ru/userfiles/file/zikidobeparitizum.pdfIn PDF document text
    • http://eszixv.hu/ckfinder/userfiles/files/lisizowo.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/a3615f3e58a0af806b132bd846fde1b4/62369028123.pdfIn PDF document text
    • http://luijkzonwering.nl/image/file/sarisovikikopowikeje.pdfIn PDF document text
    • http://businessdevelopmentcenter.pl/uploads/userfiles/files/buxajamep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=convertir+fotos+en+3d+androidPDF 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_off0000ea3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA3C 10568 bytes
SHA-256: 938176658660e545cb42b4810ee998412d0a7d7a2ce9c23c7088e463e2d1b0fd
font_01_sfnt_off00010295.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10295 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011aa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AA7 20608 bytes
SHA-256: 05d8d9b3bc0eb1262bd35bb5a1da1dda09d1864a1bbaa981dcbd79ed43a95969