Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4c53e14af2b4e3a…

MALICIOUS

PDF

73.3 KB Created: 2021-06-07 06:30:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 6f89658217f4211b11c216a0dec0a089 SHA-1: e05430bbce06135220a645929ce688c709731174 SHA-256: f4c53e14af2b4e3aba096d448ef5635947bd3dcd16992e2035e534d07855706a
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, containing numerous external URLs pointing to various PDF documents, likely to manipulate search engine results or redirect users to malicious content. The presence of external URIs and a link farm on disposable hosting suggests a phishing or SEO spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • 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.
  • 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://pistant.ru/pbw?utm_term=blokus+rules+for+3+players PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4426696/normal_6019cb40b8628.pdfIn PDF document text
    • https://tediresul.weebly.com/uploads/1/3/5/3/135345321/vufut.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410204/normal_5fff00f39edcd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444864/normal_60bd74e78ab78.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4489598/normal_5fc8587057394.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368496/normal_6011acc6b2abf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492900/normal_600f3b779e02d.pdfIn PDF document text
    • https://wajirabipuxu.weebly.com/uploads/1/3/0/8/130874591/rijaxabam.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4460463/normal_60b3cfb6e0cb7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388422/normal_603cfe4adbee8.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4455196/normal_60b721d15308a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4371023/normal_5fc7c792df231.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486765/normal_60175e436a4d4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471091/normal_60b8602cef817.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://mifimoruzuwo.pbworks.com/f/47132085588.pdfIn PDF document text
    • http://finatin.pbworks.com/w/file/fetch/144500919/what_good_movies_are_on_cinemax.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9c3b01fa-29c3-4205-9ffa-4649862230f3/xutej.pdfIn PDF document text
    • http://juvupumanut.pbworks.com/w/file/fetch/144523737/72125783736.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a5ac4c83-a69b-4ace-8899-8c64d347fb85/zabigorabizo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/275798ca-7988-4494-b64c-13dcc92a68bc/robert_harris_writing_with_clarity_and_style.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e301ab66-642c-4ae7-9b50-f34d0c6e347c/41012174785.pdfIn PDF document text
    • http://rumusapage.pbworks.com/f/examen_de_espaol_secundaria_primer_grado_segundo_bimestre.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_off0000df91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF91 5272 bytes
SHA-256: 8381b0fba59dfc1475048f75538e374337d672d66ebc4081d7f5d1c5e774f96e
font_01_sfnt_off0000f199.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF199 10936 bytes
SHA-256: 541f56fda26ec8da0838553630c27e17a1521a056bff6f4ba275f3b194415225