Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f87281424b4e5d6…

MALICIOUS

PDF

89.4 KB Created: 2021-04-23 13:15:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 283893d3399a3dfd26417347f4edf76b SHA-1: c169e7b5d5958dd2f19f328a336653816cc02b24 SHA-256: 3f87281424b4e5d6c0c57285533708f50f494f3f11965a365dfc2912c4d78fbd
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external URLs suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://mezovuduw.ru/strik?utm_term=what+causes+aggressive+behaviour+in+dogs PDF link annotation
    • https://cdn.sqhk.co/tubafejog/0o5Fnig/autoradio_bluetooth_android_audi_a4_b8.pdfIn PDF document text
    • https://cdn.sqhk.co/fepewujufa/VyhasMC/color_roll_3d_game_online_free.pdfIn PDF document text
    • https://cdn.sqhk.co/vexorikodo/ajIjdRf/perfect_piano_chords_numbers.pdfIn PDF document text
    • https://cdn.sqhk.co/tenokesime/8mcZgh2/off_road_mountain_bike_trails_leicestershire.pdfIn PDF document text
    • https://cdn.sqhk.co/togixulala/cidXaji/common_job_interview_questions_and_answers.pdfIn PDF document text
    • http://zakozoxutujo.22web.org/lexical_analyzer.pdfIn PDF document text
    • https://cdn.sqhk.co/midijanere/sgh4BX0/daxijoruwasokaluj.pdfIn PDF document text
    • http://mutedagagagexe.22web.org/18518866773.pdfIn PDF document text
    • https://cdn.sqhk.co/kamepixuxuk/jbHygdd/bleep_sound_effect_android.pdfIn PDF document text
    • https://cdn.sqhk.co/gukokefa/Awgd1q8/14060096477.pdfIn PDF document text
    • http://bakofutemuxasog.iblogger.org/vivowumawamigonetez.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wemubateba.epizy.com/tofeniropulutanapatu.pdfIn PDF document text
    • https://s3.amazonaws.com/zevutebulaworel/kepekug.pdfIn PDF document text
    • https://a39ac558-8fe8-437d-9e10-dc9402d6cb9c.filesusr.com/ugd/1ebe14_4c2bed3600f34a3c9b03c72bc29e25c2.pdf?index=trueIn PDF document text
    • https://6d706a39-1f93-4f1a-9423-caccf7e65e71.filesusr.com/ugd/69f91f_743118898c4747659c35d9dbc6f46b60.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/4d7c971e-6a44-4fcd-af7e-b16554825a91/reliabilt_doors_instructions.pdfIn PDF document text
    • https://s3.amazonaws.com/mexesazaxasa/how_to_repair_fleck_5600.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dfaf91c0-c5de-4da7-a9d5-dd463bce678f/23761262468.pdfIn PDF document text
    • https://s3.amazonaws.com/xijilesuzuxo/happy_bday_song_audio.pdfIn PDF document text
    • https://s3.amazonaws.com/gogoxowiniza/i_p_s_full_form_in_kannada.pdfIn PDF document text
    • https://s3.amazonaws.com/jejulurowev/how_to_fill_out_nichq_vanderbilt_assessment_scale.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eca79e94-9c6e-454a-a708-d57aecac6a6d/how_to_change_gauges_on_livewire_ts.pdfIn PDF document text
    • https://627ea4a7-3f28-4bf3-8c99-6a9da7dacf48.filesusr.com/ugd/1970e2_c78f1531691e47468a8e8f35c49df272.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/bebe85dc-4af4-4d0c-857d-25d95fbb3b67/dunkin_donuts_apple_cider_munchkin_ingredients.pdfIn PDF document text
    • https://73856814-13bb-4d44-aeaf-752cce6ba6bd.filesusr.com/ugd/a0d21a_9737096840b24b61bc29259fc0c5cf79.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/87188528-d0c2-4334-be55-be34c7a91327/asus_p8z77_v_deluxe_ram_compatibility.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_off00011e87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E87 5380 bytes
SHA-256: 31771f1e3dbea144199f0c148a08b7b5d8b7e9d1b1b0db6cdbb98a3bb01953f4
font_01_sfnt_off000130db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130DB 11484 bytes
SHA-256: 7200370c7846c544d3d1e8652e0c2d58e7f77a067ed3bad831a18b6485f39d85