Malicious PDF — malware analysis report

Static analysis result for SHA-256 71b4498e2c366df2…

MALICIOUS

PDF

84.9 KB Created: 2021-09-04 16:33:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ba3a514a97962bff01f94610ea907ccf SHA-1: fecfb4b7b62de18d34a3d5312afdac844d3c5b9f SHA-256: 71b4498e2c366df2eeccfba4de72cff34e9c3b349c01fe6d98caa74214065f9f
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm. The primary goal appears to be directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://queure.ru/uplcv?utm_term=yashica+mat+124g+manual PDF link annotation
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16118354139c41---32950092926.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/80090999509.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/160947bf31bb82---rogiduzarenodasugolef.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/19r3d4gkmbrlvva919sub2985q/sixisosusibum.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/rilifufonomu.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/be865890ca21ceba0358e900ad8cd9d5/68588350072.pdfIn PDF document text
    • http://pm-property.pl/userfiles/file/xipafibumaxadufes.pdfIn PDF document text
    • https://daismene.it/file/lexisolajofunileburube.pdfIn PDF document text
    • http://zs-oilfieldequip.ru/d/files/gelegabafijomiwovik.pdfIn PDF document text
    • http://szzxwx.com/Upload/Upload/file/20217101030211873.pdfIn PDF document text
    • http://m2m2design.com/userfiles/63289721950.pdfIn PDF document text
    • http://domingo.hu/ckfinder/userfiles/files/37445437911.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/phrb4pf1nnlm791jih2eojc3qm/tudam.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d3ee867812---13675266428.pdfIn PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096f0286c06f---88570654869.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/kimaxanajubiwutojegekipaj.pdfIn PDF document text
    • http://cariboohose.com/userfiles/file/25519613436.pdfIn PDF document text
    • http://hurtowniagrafit.pl/userfiles/file/viwapel.pdfIn PDF document text
    • https://camgloberealtor.com/userfiles/file/60956430783.pdfIn PDF document text
    • https://bursakaynak.com/userfiles/file/javemalevakomif.pdfIn PDF document text
    • http://www.benyowsky.com/resources/files/24228754345.pdfIn PDF document text
    • https://tinhhoaxanh.vn/userfiles/file/54260360806.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_off0000e607.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE607 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE1E 10656 bytes
SHA-256: ca4990f5ce78feedcf22d54744be587e67a63280514885f6d5fa33cb32f2f039
font_02_sfnt_off0001167d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1167D 18656 bytes
SHA-256: c4fe8e10ebbf3ec14322f3c983181590a1e6cdf6f9ce8942b8c01ecfea8746fe