Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b91a0c581d50814…

MALICIOUS

PDF

76.3 KB Created: 2021-05-18 20:53:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 9aab5a56b3872c5009dc973ef88103f2 SHA-1: dca6fd06c531571e9784c57a9ce6401a472f879c SHA-256: 1b91a0c581d50814a6d0fdc7931ba42a22d9c50fc810553ae94063026e962f08
194 Risk Score

Malware Insights

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

The PDF contains a link disguised as a free download for a book, which redirects to a known malicious URL. This indicates a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://yafferge.ru/strik?utm_term=historia+de+la+medicina+manuel+barquin+pdf+gratis In PDF document text
    • https://cdn-cms.f-static.net/uploads/4464732/normal_603c1a5c0f8d0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421199/normal_606a21ebcb4fe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366057/normal_60466b6425ad7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4406482/normal_5fdf10bcbc3de.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445739/normal_600f580629123.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368469/normal_605d8e97b105b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371246/normal_5fe86c68d017e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491687/normal_606cb4c496e9e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393369/normal_6020d097b1648.pdfIn PDF document text
    • http://jawigonoputumun.iblogger.org/kunel.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4373779/normal_6000da172dd1c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422909/normal_6026867f0d57d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478393/normal_603cfeecb7544.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/tuletivotarupu/music_apple_watch_spotify.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7ac95125-9723-4571-ba5c-c39aacb3dd56/vepunaniw.pdfIn PDF document text
    • https://s3.amazonaws.com/popilo/which_is_better_keto_box_vs_keto_krate.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/412d554a-eb22-4071-baea-76b68f11d7e8/is_2005_pt_cruiser_a_good_car.pdfIn PDF document text
    • https://s3.amazonaws.com/jopomodilamego/unabridged_birth_certificate_application_form.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dfda8815-9263-4888-b34b-9d8d6d010920/38592198627.pdfIn PDF document text
    • http://simivejed.rf.gd/princeton_review_practice_test_4_answer_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6929b525-ad41-45a2-936a-12e702b19078/55534014506.pdfIn PDF document text
    • https://s3.amazonaws.com/pukiza/how_many_voiceless_consonants_are_there.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e800.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE800 5704 bytes
SHA-256: 95123fc7bcd845c313b17688331c7780fab2dfb18b8446cca8ce4a45a6e061dc
font_01_sfnt_off0000fb3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB3D 11968 bytes
SHA-256: 881bb3b38620393eeddd9df29bc07e4f96707d19999877097d386b94bde8e270