Malicious PDF — malware analysis report

Static analysis result for SHA-256 3755b07c1be5338c…

MALICIOUS

PDF

93.4 KB Created: 2021-05-31 23:55:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 26cbc65c30a2614d43dac3208ecefbd9 SHA-1: 35c81c737423e5ca27a2ac1d9331715b1d915725 SHA-256: 3755b07c1be5338c2fb769ded9db4eda65520eca4918646783afe3303c585169
126 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 https://coretry.ru/pbw?utm_term=what+are+the+types+of+oral+literature PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4446285/normal_6050ef20687af.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4392872/normal_5fcf4e79c8c8a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375507/normal_602e0c9f9c297.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407998/normal_6063a2bb9d70b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444630/normal_60502a9c105ff.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4428335/normal_600d9f6ece9f2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423750/normal_60199949991f1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/2656f5db-1659-48c8-b4c6-d447b1f94a3b/expert_c_programming.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e112ce80-629f-438f-a248-e0a69b6e16d7/gufobizatunujozub.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c718bf4d-7f8b-4061-99f4-d62e8ddc69e7/5195592215.pdfIn PDF document text
    • http://vowujepojez.pbworks.com/w/file/fetch/144427335/54254984990.pdfIn PDF document text
    • http://xuruzinijub.pbworks.com/w/file/fetch/144423876/slumdog_millionaire_book_macmillan.pdfIn PDF document text
    • http://wuwazilizos.pbworks.com/w/file/fetch/144424473/fenuvovapulo.pdfIn PDF document text
    • http://nusuwoxub.pbworks.com/f/how_to_find_the_median_of_grouped_data.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/da7a7fc2-8236-4a87-a909-5e081096d55a/65857257872.pdfIn PDF document text
    • http://funinupun.pbworks.com/w/file/fetch/144418524/nudexumu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bebc0095-9243-4ad4-a4a6-35f1d60af49a/understanding_psychology_12th_edition.pdfIn PDF document text
    • http://wuvebag.pbworks.com/f/financial_statement_analysis_and_security_valuation_5e_by_penman_s.h.pdfIn PDF document text
    • http://zemenifinabe.pbworks.com/f/78613616211.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010f8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F8D 4880 bytes
SHA-256: de3428d443fea22f2d30d69679324e0efa992233f42b499130b9b7a55f9cdda1
font_01_sfnt_off00012050.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12050 10468 bytes
SHA-256: 79b1bd1ddd75286b1a35553107a07da2fc35d5efbe16292eb86519abd74b62fd
font_02_sfnt_off00014432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14432 16204 bytes
SHA-256: 532315dfdc59b350d447ad91845dd8cc72a836e684f536ab9a4305dc5b53fb8e
font_03_sfnt_off00015962.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15962 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c