Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d455d94fe3e9eea…

MALICIOUS

PDF

76.6 KB Created: 2021-05-29 10:02:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 4d0fd116ae24c03585e507a5c304aee0 SHA-1: 0450cdd52734dd7ffcc5df27a2f2006f3e5e3081 SHA-256: 4d455d94fe3e9eea7706710913f671b9fa20ff2e48700c87d72d843b31cb3013
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting services, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and numerous embedded URLs are indicative of malicious redirection tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://kuzutuzo.ru/strik?utm_term=ejercicios+del+presente+perfecto+y+pasado+simple PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4425235/normal_6026957a8bd53.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368493/normal_5fc715a8885a4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412897/normal_600e41c69f0a7.pdfIn PDF document text
    • https://gopaxabog.weebly.com/uploads/1/3/5/3/135309926/vidof.pdfIn PDF document text
    • https://desebenenoda.weebly.com/uploads/1/3/5/3/135348916/1548cfcf398199d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367303/normal_6019ff3d647d5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391907/normal_605d873aaeaf0.pdfIn PDF document text
    • https://jevizaja.weebly.com/uploads/1/3/4/8/134869407/01f699aa1f4e2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415045/normal_6044dcb1c8529.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383702/normal_60158d7e9b3d1.pdfIn PDF document text
    • https://jagaruwej.weebly.com/uploads/1/3/0/8/130874180/xurojule_nosobaziduzapew.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420476/normal_605303a59cd8d.pdfIn PDF document text
    • https://latabiwot.weebly.com/uploads/1/3/4/6/134612911/f8ba1d42df134bb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4485705/normal_5fc8e0ce7b984.pdfIn PDF document text
    • https://dinumaditu.weebly.com/uploads/1/3/4/4/134479473/kubovevufaxedobiz.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481516/normal_6052588459c05.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/78682f6b-e45b-4106-b167-fffdf27af286/what_are_the_different_types_of_portland_cement.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/232e9dfd-8e09-4643-afb5-cdd090971bd6/gomozesufafujilijeba.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c21b4777-52ce-482c-be96-75a54f16ac38/throne_of_glass_box_set_used.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_off0000e7ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7CE 5436 bytes
SHA-256: ce47eca243a6fa9f9b52993309894514901dfe6e413f991a8b85b405e6b6a19a
font_01_sfnt_off0000fa4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA4B 12532 bytes
SHA-256: f74999969e6527f1cedbf463ce3b30243b6d57f5be856a5387c08aba39fce1f6