Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ae220875f76a35…

MALICIOUS

PDF

89.5 KB Created: 2021-03-30 08:45:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 3a6af8325b807dd57daa5dc9ea2e9ae5 SHA-1: d82c53d1dca7b87062fb08f1ef4cae34b0c7394d SHA-256: 81ae220875f76a359c4c6e7ddc9d0efc0ba790c567c77220808388611d072478
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

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://baarspo.ru/123?utm_term=neumonia+pediatria+pdf+2017+colombia PDF link annotation
    • http://manapuzasupin.sportsontheweb.net/railway_bridges_and_tunnels_book.pdfIn PDF document text
    • http://namumexazezi.22web.org/how_to_download_brushes_for_procreate.pdfIn PDF document text
    • https://cdn.sqhk.co/kevekelobivo/vnD5Lhe/apple_credit_card_swiper_for_iphone.pdfIn PDF document text
    • https://cdn.sqhk.co/filodomazora/mhcjecE/euphoria_bts_letra_answer.pdfIn PDF document text
    • http://pifedalune.medianewsonline.com/skf_ball_bearing_catalogue_free_download.pdfIn PDF document text
    • https://cdn.sqhk.co/guludagew/jhjRjci/box_packaging_template_psd.pdfIn PDF document text
    • http://manaluw.iblogger.org/poxasujatanudira.pdfIn PDF document text
    • http://ketuzel.22web.org/coco_family_tree_worksheet_spanish.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/f462e4dc-60ca-4c6b-a09a-9bd441ddd789/heidelberg_catechism_116.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/90da5f4b-a7b1-4db8-abd5-fc1f37d75319/will_mini_14_mags_fit_mini_30.pdfIn PDF document text
    • http://fiwujugisijema.epizy.com/ayo_and_teo_christmas_song.pdfIn PDF document text
    • https://ea7788ad-ef5a-48b5-911d-3ad522045378.filesusr.com/ugd/f3bfbb_9bbfff7241d94b36827707edef9c808f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/bb5862d4-0a80-4eca-94b9-3fd235a81360/suzimaj.pdfIn PDF document text
    • https://59548cc9-d6a6-4b2e-bd73-2bfb7290c7b5.filesusr.com/ugd/3fd21f_6dfd68cd47984e14b9c701ccc95f3b30.pdf?index=trueIn PDF document text
    • http://wabelofug.rf.gd/what_is_the_brain_stimulation_method.pdfIn PDF document text
    • http://medexode.atwebpages.com/59426508026.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/51bc7da2-23e9-4556-a789-855fb9d11e01/video_games_lana_del_rey_cover_tiktok.pdfIn PDF document text
    • http://vutagefen.epizy.com/alp_rrb_answer_key_grade_up.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/50dbde84-761d-40a0-a0ab-bfdf6d9752a7/what_does_hard_cheese_mean_slang.pdfIn PDF document text
    • http://pidosowot.epizy.com/41901909445.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_off00011bf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BF8 5636 bytes
SHA-256: 12085b0d522a18b113041aa6e17b0e2d1e49ac58be30a2181262eaf5be205463
font_01_sfnt_off00012f12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F12 12472 bytes
SHA-256: f4c128f63524c291a47a86eb7b3301885b94922f3589d899861075cb271a6b7f