Malicious PDF — malware analysis report

Static analysis result for SHA-256 72ec96c5693267bf…

MALICIOUS

PDF

83.2 KB Created: 2021-03-22 17:03:41 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: c30060114642568f78581c99cae86034 SHA-1: 6d7153d9ef98eeb04518d0d49e04f1617f78909c SHA-256: 72ec96c5693267bf86bf2ca0b3203bcf1d00b64efc35eb88134ca61686622ed0
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs, many pointing to disposable hosting, suggesting a link farm or phishing operation. The document body, though heavily corrupted, contains text related to 'answer key' and 'wkhtmltopdf', reinforcing the lure. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest the document's purpose is to redirect users to malicious sites for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://botokaw.ru/wix?keyword=discovering+fiction+1+answer+key+pdf PDF link annotation
    • https://medekokimezud.weebly.com/uploads/1/3/4/7/134748457/sizeroxipebiwaf.pdfIn PDF document text
    • http://brosbass.com/genetics_vocabulary_practice_and_review_answer_keykfy95.pdfIn PDF document text
    • https://riviruzo.weebly.com/uploads/1/3/0/7/130739493/sivir_pagogej.pdfIn PDF document text
    • https://cdn.sqhk.co/renosopezare/hghfVij/wings_financial_around_me.pdfIn PDF document text
    • http://lnstagramcopyrigtservice.com/balloon_bubble_gamebc1r2.pdfIn PDF document text
    • https://dewisepiremutu.weebly.com/uploads/1/3/4/3/134318599/3246185.pdfIn PDF document text
    • http://filfex.ru/samsung_smart_tv_55_inch_price_philippinesro22n.pdfIn PDF document text
    • http://trastenmyqort.online/marantz_tape_deck4fk7a.pdfIn PDF document text
    • https://cdn.sqhk.co/nefowumik/ja4Dugj/bajrangi_song_telugu.pdfIn PDF document text
    • https://cdn.sqhk.co/bulixanejad/egcibif/can_you_escape_this_house_2_level_8.pdfIn PDF document text
    • http://d2-club.ru/free_printable_math_worksheets_for_2nd_grade_word_problemsgaynv.pdfIn PDF document text
    • http://kokulet.22web.org/zosupopex.pdfIn PDF document text
    • https://cdn.sqhk.co/bikegola/fGhfjjF/vital_skills_study_strategies.pdfIn PDF document text
    • https://fiwisito.weebly.com/uploads/1/3/4/7/134715438/4028322.pdfIn PDF document text
    • http://tadukesavexufe.22web.org/94866440896.pdfIn PDF document text
    • https://cdn.sqhk.co/wuvotalek/i1Ijija/highway_rider_bike_racing_game.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
    • https://28546a20-d0cc-4b82-bb4f-6711990cd5a3.filesusr.com/ugd/0bcf16_889ff18213a84138bbcf04ef2ffe1ee8.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/855f49db-fa4b-41f8-8974-15d7c051e784/wuxipuxopuxew.pdfIn PDF document text
    • http://lojarine.epizy.com/what_is_the_learning_theory_in_psychology.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ba1f4606-210f-4094-bac6-8967ee9d335a/85781043134.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aed37fba-3f97-4444-8f4c-c1e385239b6e/professions_and_occupations_worksheets.pdfIn PDF document text
    • https://d5cf7a15-73c9-49c9-ad57-d4f0303abb0c.filesusr.com/ugd/0d002d_308aaff33baf408a89335e78cea50662.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/6826a3ee-945d-4ce3-829a-1fdf8335110c/32544461699.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_off0000f6e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E6 5448 bytes
SHA-256: 12fcd2a5188660247cebafeddca8b25cf92d64a8094dbe7c63ee3010a88912b1
font_01_sfnt_off0001099b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1099B 11652 bytes
SHA-256: c8710fcb3c12630aae5527edfceb6328c8b540f0bd225869e08bffc6d9dd3a00
font_02_sfnt_off000130a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130A2 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230