Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4bf7ac3e7e6d191…

MALICIOUS

PDF

79.6 KB Created: 2021-03-24 15:21:43 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 57614966dec2af32ced061991a2cc496 SHA-1: 9846ee4b69d1c5d69264e896a8ce433457dd2894 SHA-256: e4bf7ac3e7e6d1917e2acf93737d6300c0dcea928e7cccd5078bd65171f5261f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links pointing to other PDF files, many hosted on disposable domains. This behavior is indicative of a link farm, often used for SEO manipulation or to distribute malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. While no scripts were extracted, the sheer volume of suspicious external links suggests a high likelihood of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://pelibifir.ru/strik?utm_term=2005+pathfinder+transmission+issues PDF link annotation
    • http://megiloreb.mypressonline.com/23756837736.pdfIn PDF document text
    • http://fawaxifiwuzodil.scienceontheweb.net/wukigupim.pdfIn PDF document text
    • https://cdn.sqhk.co/wuwexosul/2hhabT7/best_farm_for_apple_picking_long_island.pdfIn PDF document text
    • http://mokemowowove.mygamesonline.org/john_deere_gator_parts_for_sale_uk.pdfIn PDF document text
    • https://cdn.sqhk.co/lepagesali/jngvxMt/51902166869.pdfIn PDF document text
    • https://cdn.sqhk.co/pajugeluj/SctUjIY/41721541572.pdfIn PDF document text
    • https://cdn.sqhk.co/mezugifosa/6hfhcSx/mechanical_keyboard_switch_colors_explained.pdfIn PDF document text
    • https://cdn.sqhk.co/vapiwibisa/4heYh0r/zogobuzavisujogikitusozex.pdfIn PDF document text
    • https://cdn.sqhk.co/pigajifaw/YijahiD/boxijafuburapobo.pdfIn PDF document text
    • https://cdn.sqhk.co/zifegowuf/7hgLYje/xanigusivemobonuti.pdfIn PDF document text
    • http://nupesupo.mypressonline.com/xuserim.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/f7f2843e-e2c6-4c4e-8962-fe5be881740e/kabuzebevogama.pdfIn PDF document text
    • http://kivozusemu.atwebpages.com/what_is_a_paragraph_proof.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc8100c1-85ff-4172-8759-0a05c5baedf3/what_equipment_is_needed_for_a_car_wash.pdfIn PDF document text
    • https://e5acd528-9925-4355-98ed-6c6122c9c19a.filesusr.com/ugd/49fecd_a636c59c2e17474fb2cb94ac3a68b39e.pdf?index=trueIn PDF document text
    • https://81da36f4-dec6-4bf4-836b-19ed67500659.filesusr.com/ugd/5fd5c1_8e4fba184d044285a1a0a784cfc20baf.pdf?index=trueIn PDF document text
    • https://1628ddcf-e301-416d-9649-d9339b85441b.filesusr.com/ugd/0b1079_55918359163941f3b910ef7a587b55d6.pdf?index=trueIn PDF document text
    • https://e824aeac-d22a-4b45-bb3c-17051d6ee04f.filesusr.com/ugd/de60da_2177ada2298c4443a011cb2ff4a237a8.pdf?index=trueIn PDF document text
    • https://911f1565-2faa-4874-b261-330d521e7362.filesusr.com/ugd/f46427_88f4d78df5d04741bb5d6af790e1c6ed.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/66590068-5abe-4854-bad3-88ddf3820e58/what_is_the_spiritual_meaning_of_2220.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_off0000f83d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF83D 5552 bytes
SHA-256: 4ec5cc624fedbb42ff3f82bf0490f71ceb93c9bc4056e8c3d315fad03a0442bd
font_01_sfnt_off00010af7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF7 11156 bytes
SHA-256: 93d3dc7c663f16b4a69325b82a26bd493ee8596edf5174a931aab4a00a8832f8

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