Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8c8563859fb82f8…

MALICIOUS

PDF

78.3 KB Created: 2021-03-29 17:15:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4a997bbeeb739e39f33afc61cc21036e SHA-1: d0fb8e781b73fabcb1e2bdaacd35b51d9d00e259 SHA-256: b8c8563859fb82f829cd02058b71fb1eafb201b9361f38a6b3160ea784b2fac5
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, which is indicative of a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host numerous URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 6

  • 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.
  • 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://dugedepap.ru/wix?keyword=states+in+malaysia
    • http://bofinaposo.iblogger.org/garbage_in_garbage_out_ielts_reading_answer.pdf
    • http://suzofovolavuk.scienceontheweb.net/the_american_scholar_emerson_theme.pdf
    • http://zuzatew.medianewsonline.com/what_old_movies_are_on_hulu.pdf
    • http://gedagefi.22web.org/86327409228.pdf
    • http://kaxiwemusemoj.mypressonline.com/fifuxuzosokolijavipudujev.pdf
    • http://ladujose.sportsontheweb.net/xemibosafunugarefuw.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://wokarodefi.onlinewebshop.net/33906212514.pdf
    • https://05282879-aed3-4f16-ac14-d534add4d4bd.filesusr.com/ugd/0f8b7c_efa1aba6ef264368bc78701072ce9393.pdf?index=true
    • https://7fc1e5b2-1dd8-4457-9de2-3dea1ab9f589.filesusr.com/ugd/fedd61_9b2841cf661d42b5b719795def9192ad.pdf?index=true
    • https://9e730ba1-499c-413e-9a09-8a81f8121270.filesusr.com/ugd/0a0016_7311c36c83b64b63b90d8849b398bc63.pdf?index=true
    • https://uploads.strikinglycdn.com/files/7489556b-3206-4bef-a215-68fd60e4a534/jim_pattison_net_worth_2018.pdf
    • https://uploads.strikinglycdn.com/files/a4b742ce-2b28-4fe5-9ba3-8cd09bf641a9/3935184671.pdf
    • https://562c2315-396f-49d1-9e45-1236e049cb13.filesusr.com/ugd/ec0012_5970c030134f4ec58ab40c90dcdb08b8.pdf?index=true
    • https://s3.amazonaws.com/vibasujefir/high_school_transcript_template_for_homeschool.pdf
    • https://7e073981-ad1c-4081-8dc0-76946ba36063.filesusr.com/ugd/c4f63d_55a1a781a94e44088ba69833b5d3985d.pdf?index=true
    • https://uploads.strikinglycdn.com/files/f39eed9a-2a6d-4e6b-acbf-14d4292eb4c9/dirt_devil_power_stick_filter_walmart.pdf
    • https://uploads.strikinglycdn.com/files/c3fdb6f7-bd49-4ae5-a846-04fc069814f8/sony_playstation_remote_control_instructions.pdf
    • https://8a89c5bc-485b-4808-980c-66c60e8d9908.filesusr.com/ugd/834936_5f8dba13512f4b4cbddb9545da753e07.pdf?index=true
    • https://uploads.strikinglycdn.com/files/95cce24a-f2ca-4458-98d8-b3ba591caea7/a_dance_of_dragons_audiobook.pdf
    • https://s3.amazonaws.com/jimugivos/1995_7.3_powerstroke_fuel_system_diagram.pdf
    • https://b3a8b944-ddec-4d17-9b53-5a1c05c66d8c.filesusr.com/ugd/314503_f779da5825034d7888bc705907dd9bdc.pdf?index=true
    • https://s3.amazonaws.com/buganabowumujef/furug.pdf
    • https://377d1c6c-8747-407e-9a0d-bb8234813250.filesusr.com/ugd/f0b1fd_481907c30ead406085b559cad29c6ba5.pdf?index=true
    • http://sebuzozogari.epizy.com/97344376781.pdf
    • https://s3.amazonaws.com/fadadedezeker/trials_of_apollo_book_5_online_free.pdf
    • http://kujinid.rf.gd/sibumokobedeli.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f31b.bin
5cd3be0725a8eaade235c8805fee99bd53be06c1936e1c4f04d9bd523284f4c0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF31B 4940 bytes
font_01_sfnt_off000103db.bin
5fde7b198eda945c8ac455fcdd4c285c75f377601948d5a0ab47dd48c0d8fb22
pdf-font-stream PDF embedded font (sfnt) at offset 0x103DB 11236 bytes