Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1785fad37f9e071…

MALICIOUS

PDF

80.4 KB Created: 2021-09-18 07:25:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5c55082a3caa617abb45af91878d476b SHA-1: 91aa162cba32775350385e268575df222eaf0568 SHA-256: b1785fad37f9e07168b705eaffea17e6fa0991b36d50996c536d084a9d94952a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with multiple embedded URLs pointing to compromised CMS uploads and disposable hosting. The document body was unreadable, but the presence of numerous external links suggests an attempt to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://dynamicyunnan.com/ckfinder/userfiles/files/wifowedezokijisa.pdf In PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/u7ss9kb5o4vp995ofenqanivb0/27633189140.pdfIn PDF document text
    • https://bc2000.order-pro.com/ckfinder/userfiles/files/jusavoporerilaw.pdfIn PDF document text
    • https://noelex22.org/userfiles/file/wogabu.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f9797ce6cc---watawegifopoxim.pdfIn PDF document text
    • http://hamlineparkplaza.com/assets/amund/ckfinder/userfiles/files/47952209659.pdfIn PDF document text
    • https://kiaavcilar.com/upload/ckfinder/files/71283809760.pdfIn PDF document text
    • http://transportdiverse.com/uploads/files/64673850568.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/6200274302.pdfIn PDF document text
    • http://generalaudit.pl/eurostyl/photos/file/80984894089.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4840b770c---16565135233.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/17119517689.pdfIn PDF document text
    • http://agriturismolataggiasca.eu/userfiles/files/fevis.pdfIn PDF document text
    • https://univerosg.com/ckfinder/userfiles/files/88332369102.pdfIn PDF document text
    • https://cicasoftavukatwebsitesi.demowebsiteleri.com/upload/files/62551338235.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/lonom.pdfIn PDF document text
    • http://peak-experience-japan.com/images/blog/file/13235566963.pdfIn PDF document text
    • http://bluekeydigital.com/images/pic/file/32236166130.pdfIn PDF document text
    • http://windmill-bv.com/userfiles/files/rerafagaxugotaruxez.pdfIn PDF document text
    • http://studiotipaldo.com/userfiles/files/piguxejowes.pdfIn PDF document text
    • https://sukaunited4d.vip/contents/files/57957130212.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/90130152721.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=free+online+porn+games+for+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://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_off0000da6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA6F 10720 bytes
SHA-256: 79a114a16a3a35ec12c48f3c224b9f112a2b138e180d27ed8b393ec26630b832
font_01_sfnt_off0000f2bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BB 18168 bytes
SHA-256: eb81ce8cb2dfccd75ee3f5026109ccc2231a3c93531e7da75308519d70247948
font_02_sfnt_off000121fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1