Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b83ad25bc05a91…

MALICIOUS

PDF

78.0 KB Created: 2021-04-20 19:48:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 18961eafaadf7aaa0e11473e7bd1dfc3 SHA-1: aadd781bc7e7dcd583b20319010aefb5cf3dd3d4 SHA-256: 81b83ad25bc05a91e59a35fb3e37359a98fa85574e95c754287b6e8699caa56e
186 Risk Score

Malware Insights

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

The PDF file contains a link farm with 30 external links, many hosted on disposable domains, suggesting a phishing or SEO spam campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing lure designed to redirect users to malicious content.

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://xezojetit.ru/strik?utm_term=what+is+an+article+in+a+newspaper PDF link annotation
    • https://fagezatev.weebly.com/uploads/1/3/4/7/134711774/9661296.pdfIn PDF document text
    • http://xatakafigudu.getenjoyment.net/how_to_connect_hp_deskjet_3051a_wireless.pdfIn PDF document text
    • https://tiwudusakuwizir.weebly.com/uploads/1/3/1/6/131637104/3fa249cbd2.pdfIn PDF document text
    • https://vabeliguteziji.weebly.com/uploads/1/3/1/3/131379360/zitokizadatubinuxon.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500200/normal_600f63143657c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367617/normal_601854a12d9c1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483346/normal_5fe6f8746bfd1.pdfIn PDF document text
    • https://kirewigofe.weebly.com/uploads/1/3/4/3/134382955/8603132.pdfIn PDF document text
    • https://kekoweditolig.weebly.com/uploads/1/3/2/6/132683085/2286489.pdfIn PDF document text
    • http://sesesuruko.mypressonline.com/3ds_max_building_modelling_tutorials.pdfIn PDF document text
    • http://noxitafevinuv.22web.org/badrinath_tamil_dubbed_movie_free.pdfIn PDF document text
    • http://wapadax.scienceontheweb.net/critical_race_theory_third_edition.pdfIn PDF document text
    • http://mekujoviwe.mypressonline.com/all_network_topologies.pdfIn PDF document text
    • https://tumokisomagen.weebly.com/uploads/1/3/4/8/134897409/sukanodiwi.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
    • http://kewivawegimomu.epizy.com/zerobekibuvajuza.pdfIn PDF document text
    • http://vatapusaf.rf.gd/64117759476.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e469.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE469 4804 bytes
SHA-256: 59b602550823e36b22eb9d33f0338e60c76e1809fb9376afdf0e92801bdb7351
font_01_sfnt_off0000f4ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BA 11756 bytes
SHA-256: 448c86d2456a2bf7b1ad753f886d1058cb3c9f862d224428d607308764c24091
font_02_sfnt_off00011c56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C56 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c

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