Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4894d67c653dbff…

MALICIOUS

PDF

71.2 KB Created: 2021-04-04 16:29:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 88d5d4b13f773ceb3c7d6997cc119d30 SHA-1: 253a34ea9bfd52e8524d27c9fcf95d3cd787f789 SHA-256: a4894d67c653dbff4b502c814c2e583e58ae90cc5d475e8c8606724bbe3e5827
186 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains a large number of external links, many hosted on disposable domains, suggesting it is part of a link farm designed for SEO manipulation or to distribute further malicious content. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of malicious intent, likely related to phishing or malware distribution.

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://jacksth.ru/award?keyword=automata+theory+and+computability+by+padma+reddy+pdf+free+download PDF link annotation
    • https://cdn.sqhk.co/nifodotiriru/icdyaif/68599425706.pdfIn PDF document text
    • https://cdn.sqhk.co/mukujoripu/1rgddg8/82955068742.pdfIn PDF document text
    • https://cdn.sqhk.co/kejopala/njbCT6Y/new_car_sales_tax_calculator_california.pdfIn PDF document text
    • https://cdn.sqhk.co/sugefixa/hghhhfs/block_hexa_puzzle_board_game.pdfIn PDF document text
    • https://cdn.sqhk.co/ranetixeba/0PhbVXp/strike_fortress_box_mod_apk_download.pdfIn PDF document text
    • https://cdn.sqhk.co/fuzokikili/ihYggD4/barber_shops_open_tomorrow.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://pabipinipimano.epizy.com/homelite_vi_super_2_chainsaw_parts.pdfIn PDF document text
    • http://wujawejibizub.epizy.com/38175362143.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5b435864-737f-4276-88d5-10ea20a737a5/how_long_can_a_deer_live_without_food_and_water.pdfIn PDF document text
    • https://2ddf8be6-044d-4f30-b6fd-16c032829cd6.filesusr.com/ugd/9827ea_ff6dfb68e51b4db6b415f72f76fb8d96.pdf?index=trueIn PDF document text
    • https://5fa60de5-32ab-41ac-ba65-77330e21e623.filesusr.com/ugd/2e16aa_aea7a7480a9d4e37be74746e04b28a5e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/350884ca-2e4d-4807-bbe8-8c9ec9bdd4d1/job_interview_questions_and_answers_for_electronics_engineers.pdfIn PDF document text
    • https://4abf464d-34d5-4c80-8de5-e64f30e04530.filesusr.com/ugd/8b3eb5_9fda1838b624458f9ab00fffc110f2a6.pdf?index=trueIn PDF document text
    • https://f26e6bca-ce10-4524-9610-ed5ef7c8d48b.filesusr.com/ugd/ac8c68_d7d7e1849f404850bafcdedc319bc79c.pdf?index=trueIn PDF document text
    • https://59cf682b-6680-4a08-8b8d-0472bab64ef7.filesusr.com/ugd/d7d6cd_2165f44893f24544ae2e5b142a0849a8.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f37a2de9-be71-4c9f-a355-c0025838ec0e/best_celestron_nexstar.pdfIn PDF document text
    • http://zifasodokid.epizy.com/sosavalotulisod.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_off0000d931.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD931 5540 bytes
SHA-256: 99d74df1363891e78d10dd3e368e7a6e1d6cc2685917300f967fd1e16c2d0ab2
font_01_sfnt_off0000ebef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEF 10320 bytes
SHA-256: b5afbcad48b66f8f86fbf1d19e293a55f15818b0f4d669815b088ccad0d157e4