Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b9e4a4b2bd56888…

MALICIOUS

PDF

128.9 KB Created: 2021-06-01 15:54:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 8f73985554e4d4e1003a6ebe7456ba93 SHA-1: d713491b82435ecad43a1b91770712c5239efbb7 SHA-256: 0b9e4a4b2bd56888b7cbfaccb3146155c5c80ae3d18c86abdc8db9698e85178d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by 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 0.9997

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://crophysi.ru/123?utm_term=tinker+board+android PDF link annotation
    • https://kurepisafigovu.weebly.com/uploads/1/3/1/3/131398088/penofigef.pdfIn PDF document text
    • https://zavetogodafewer.weebly.com/uploads/1/3/4/7/134709275/5505247.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459325/normal_601c943782cdf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4428054/normal_60026c389ffbf.pdfIn PDF document text
    • https://revugegan.weebly.com/uploads/1/3/4/6/134682990/8922951.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://japomajuxire.pbworks.com/f/pijafarixav.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/95f6485c-cbb5-48e4-8742-e0e8480e8bb2/43645409513.pdfIn PDF document text
    • http://mikabipi.pbworks.com/w/file/fetch/144432618/how_long_does_speed_queen_dryer_take.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/63047adb-d8cf-4b3e-b93a-ee649cbd84c9/carpenters_blocks_1.8_9_minecraft.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b47a791e-44f2-4c5e-8433-c81bd2b02d0c/semekaxerurinugalipa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/79b342cf-b931-422d-8e16-85268b76205a/65977573099.pdfIn PDF document text
    • http://fulusivijomu.pbworks.com/w/file/fetch/144438483/aptitude_questions_english_with_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e3e72faf-11d0-4472-a597-013ec23025ae/kojukapujetapeb.pdfIn PDF document text
    • http://barumena.pbworks.com/w/file/fetch/144440280/download_apk_dan_data_need_for_speed_underground_2.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ef1f5ca4-52f5-49cd-8c65-a83ae1dc62d6/how_to_get_grants_for_non_profit_organization_canada.pdfIn PDF document text
    • http://naxenuve.pbworks.com/w/file/fetch/144448887/how_do_i_reset_my_logitech_mk710.pdfIn PDF document text
    • http://kolasotosexu.pbworks.com/f/what_qualifies_for_early_withdrawal_of_401k.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7fab96b1-7ffa-4667-80eb-81cd022e8e36/how_to_show_hide_formula_bar_in_excel.pdfIn PDF document text
    • http://nagomax.pbworks.com/w/file/fetch/144425265/dd_ship_map_maker.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001a640.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A640 4760 bytes
SHA-256: e06c274c92ad7ca668791ba87bf7fcd1466ca5f1ec80531dfe1bcc2f600ec3fc
font_01_sfnt_off0001b67d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B67D 12456 bytes
SHA-256: 2609170c741cfb5d95fb7fa013ef7797c290837a7b388836da4b6d52b394a288
font_02_sfnt_off0001e0f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E0F1 16072 bytes
SHA-256: f0406f8caea753d6e85877bb79d5bffc070628cb70b4ca7a47dccb6851f2375c