Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7f3f2385b51ea34…

MALICIOUS

PDF

96.9 KB Created: 2021-05-30 08:30:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 6d78d84ebf6f967e81893d94015b8194 SHA-1: 3ede57b464a1ad0554bf1d052dc685902939354d SHA-256: c7f3f2385b51ea34fb5bfa817594cfce013889bedf0491408cc240b72ddb0c4d
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links to other PDFs, indicating a link farm strategy. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or SEO abuse. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jacksth.ru/strik?utm_term=proyecto+de+investigaci%25C3%25B3n+educativa+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4452395/normal_6049f11731311.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368221/normal_602d49ee0b2ec.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489061/normal_604f6890c86ed.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365580/normal_600b71e589539.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4466689/normal_605f345618688.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406809/normal_604ef483d5679.pdfIn PDF document text
    • https://keduwamiboru.weebly.com/uploads/1/3/4/6/134669925/xenixefijij-newufowijevur-gaxinufa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450628/normal_602f38c6c0213.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366041/normal_605c5a3d63e68.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469860/normal_605b7e366b3f1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483338/normal_6069a3bd25cf0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4464530/normal_5fede4e96df1a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383679/normal_60545448a3e07.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420034/normal_5fcbbcab0f1a9.pdfIn PDF document text
    • https://jafofuwozag.weebly.com/uploads/1/3/4/3/134320688/fa70e9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486534/normal_5ffa714732695.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/9c772eb2-15cc-4f34-a95b-3f231398beef/poulan_woodshark_14_inch_chainsaw_parts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd43ee86-7211-41f3-a507-887f285cb0c7/tuberculosis_vaccine_near_me.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2aaac1dd-c725-4fc2-872f-f227e4068ecd/spirit_airlines_assessment_test_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e5297b6e-f378-4279-944a-c8fda0515e50/rivezuwime.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9e47133a-9821-49f7-9c4c-8bf4dbdd78c5/punilixeba.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a0589b3-410b-4234-880a-cf8d8416ec0e/kotenebitod.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b130bd9f-d9d9-483b-a21a-4fa1d2d132d2/vikogozokujewagune.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c1dc9ff4-b016-4ec8-9e60-47230f7b1925/what_is_the_summary_of_life_of_pi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8a2eab8a-9ef3-49e9-bf9a-8c4891e4d989/buffalo_rice_cooker_singapore_review.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_off00013994.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13994 5588 bytes
SHA-256: c7b078af33071231bcdfe4fad3d71608c8c804bc54464b93e4f1ccdb9d8c0839
font_01_sfnt_off00014c7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C7A 11988 bytes
SHA-256: 6e7ad177bddc0adcc713fa58650d123d0367d63f435aa1f4794c76956aaeffa0