Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb7b9ca179461e29…

MALICIOUS

PDF

84.7 KB Created: 2021-03-08 19:58:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: ee2740eb3412ae73cf8b19844ad401f2 SHA-1: 4b6d2230db4bba924ef45dfeb1a764db34c00e01 SHA-256: fb7b9ca179461e2998b7c2d5a4c6f7d1297e04b2b20f24d935b179c0f24de62e
126 Risk Score

Malware Insights

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

The PDF file contains heuristics indicating it is a link farm and hosts external URIs, specifically pointing to a URL that impersonates an answer sheet for a TOEIC exam. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a social engineering attack to redirect users to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 5

  • 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 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://jumiwimov.ru/award?keyword=answer+sheet+toeic+ets+pdf PDF link annotation
    • https://cdn.sqhk.co/lusajiki/dgegcpd/gojugijibuxazakefidugoxa.pdfIn PDF document text
    • https://vilofezilo.weebly.com/uploads/1/3/0/7/130740065/b3f219df206a.pdfIn PDF document text
    • https://cdn.sqhk.co/tatogevi/aUgdNid/gilufaxutusaseripugonabif.pdfIn PDF document text
    • https://cdn.sqhk.co/zozimevoket/jhzrRWe/5496612538.pdfIn PDF document text
    • https://revawowi.weebly.com/uploads/1/3/5/3/135317167/siginurilalow.pdfIn PDF document text
    • https://wanujonoguj.weebly.com/uploads/1/3/1/6/131607110/ratowiwu.pdfIn PDF document text
    • https://cdn.sqhk.co/xataruzepape/hjcmlKq/bloomsburg_university_bookstore_summer_hours.pdfIn PDF document text
    • https://gopadafuwidu.weebly.com/uploads/1/3/0/7/130740623/jukewetoji.pdfIn PDF document text
    • https://vowipolijej.weebly.com/uploads/1/3/4/7/134713390/pufexezemiru.pdfIn PDF document text
    • https://fiwibafufo.weebly.com/uploads/1/3/0/7/130774969/kunutarufigupa.pdfIn PDF document text
    • https://sumigixutaruxaj.weebly.com/uploads/1/3/4/7/134748626/kukipokijikoz.pdfIn PDF document text
    • http://rawoxaxevog.mygamesonline.org/sewame.pdfIn PDF document text
    • http://jajuviramigawo.medianewsonline.com/53527425628.pdfIn PDF document text
    • https://cdn.sqhk.co/pafatewodoju/hh4gjif/bonawubada.pdfIn PDF document text
    • https://ximetekorexuven.weebly.com/uploads/1/3/4/4/134489871/vibabapaxato.pdfIn PDF document text
    • https://fudesatalaponu.weebly.com/uploads/1/3/2/7/132710537/806767.pdfIn PDF document text
    • http://jixazepo.mywebcommunity.org/doluwasuboxojigu.pdfIn PDF document text
    • http://zemesod.getenjoyment.net/porozevafav.pdfIn PDF document text
    • http://finomimetafix.sportsontheweb.net/miluxovudujemutanopusu.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/22ac7cf0-18c3-45c8-84fe-45e07d7f4dfa/setiforosiwokukunafe.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/60fd4725-ae8c-4438-a0a3-9e42634d06ff/beginner_5k_training_plan_reddit.pdfIn PDF document text
    • http://nizowozutagele.atwebpages.com/19018087516.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7c4d212a-4547-47aa-acaf-6fe9f20a629a/tewoturetiji.pdfIn PDF document text
    • http://keregimuw.onlinewebshop.net/how_to_make_probability_distribution_table_in_excel.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/24cc51fe-86b3-495a-b06c-47cd3ac2eca6/what_do_green_tree_frogs_eat_besides_insects.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1e39f64f-bdef-4d1b-a222-2ef901bb1ba0/mimewikogafexoraferenasa.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C0 5084 bytes
SHA-256: 762ce591358913e9d50ece84eb4fcc632627f4b3faec88e22bfde44e89c573ce
font_01_sfnt_off0000f821.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF821 19224 bytes
SHA-256: 7cf9167dbe404111be8aa40453b958b150ab18b4f1467e65d85a2bfa05bf8720
font_02_sfnt_off00012e42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E42 16060 bytes
SHA-256: eb67323a3edc51f073cf7ae7c668a4400309481d93a41d1ca3bfc03d889966df