Malicious PDF — malware analysis report

Static analysis result for SHA-256 666183e92409ed19…

MALICIOUS

PDF

75.1 KB Created: 2021-06-03 05:42:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: ac559773ac7bfc192d675b397858c1b5 SHA-1: ca6ee928997fa08355d0471efa8623842e9a09d1 SHA-256: 666183e92409ed19f2c03b4c49776474d83c77ae485f92f3526dd2ecd6ba98af
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, but the sheer volume of external links is the primary indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://leonvi.ru/123?utm_term=androidx+lifecycle+ktx PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4427528/normal_60100555b8cd0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415530/normal_6043ffa9b7aeb.pdfIn PDF document text
    • https://domekemukud.weebly.com/uploads/1/3/5/3/135327345/newapawirex_wofakodelokeg.pdfIn PDF document text
    • https://gusobukenifoku.weebly.com/uploads/1/3/4/5/134525986/nosebixemanuto.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481695/normal_5fca4a749d387.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492245/normal_60281f4e61bb1.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4480732/normal_60b72b1ad4807.pdfIn PDF document text
    • https://tikemedatimi.weebly.com/uploads/1/3/0/7/130776462/7406733.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415309/normal_5fef46fd14d8d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408588/normal_5fcda1c822ab6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417414/normal_5fcaf16f8649e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454436/normal_60446b339597a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470535/normal_6062407aa6237.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413845/normal_6003ad488b345.pdfIn PDF document text
    • https://werovowota.weebly.com/uploads/1/3/4/7/134766705/9309119.pdfIn PDF document text
    • https://dokojivoko.weebly.com/uploads/1/3/4/3/134395563/bd8623e6d1ca.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/d3ad2e1a-cbcb-4b8d-8fb1-3e28e465eb0f/4.2_relations_and_functions_worksheet_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9f60ce89-6a22-4593-9f54-b7e263f91873/love_is_in_the_earth_the_crystal__mineral_encyclopedia.pdfIn PDF document text
    • http://sozakuvepar.pbworks.com/w/file/fetch/144506460/97264473891.pdfIn PDF document text
    • http://kuperuxowix.pbworks.com/w/file/fetch/144533757/67906124028.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_off0000e5fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5FB 4852 bytes
SHA-256: ce37376f80a45717e66e8cdbdff77b30fb47b4d26da95e2a1681cbf0c543d7cf
font_01_sfnt_off0000f699.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF699 12080 bytes
SHA-256: fd6dfeb851e4661306eaea7c84c35688e69bdd7049baa462dd58f515ddba580d