Malicious PDF — malware analysis report

Static analysis result for SHA-256 509c83c469cf5e81…

MALICIOUS

PDF

71.3 KB Created: 2021-06-05 21:16:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 50352c3f4d83d67597c3924f5c550ecc SHA-1: ca880721ecb4a9b3db7e4a31946d3e09953e8395 SHA-256: 509c83c469cf5e81b12d57f72927ec0f9e1c90b3f7a99a3b01d883ab8dfdd4d4
126 Risk Score

Malware Insights

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

The PDF file contains embedded URLs, one of which points to a suspicious domain ('golowaki.ru') that is likely part of a phishing or malicious content delivery scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF is designed to host multiple links, suggesting a tactic to distribute malicious content or phish for information. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://golowaki.ru/123?utm_term=slope+intercept+form+khan+academy+practice PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4386851/normal_606353a319d10.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402520/normal_603a710c69c61.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371809/normal_6048f62b0dd8a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4501029/normal_5ff27bfad3ca6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391620/normal_60b7bca72458d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375690/normal_60414e0e19278.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454304/normal_60415a33c5dc2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490129/normal_606d4d2255e93.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4388173/normal_5fcd84bb9a2fc.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4471464/normal_5fe5fb4f18f06.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424982/normal_604cba0bc2e52.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://zeladejan.pbworks.com/f/degelewozupemobevavibak.pdfIn PDF document text
    • http://lururefisu.pbworks.com/f/94257555337.pdfIn PDF document text
    • http://xedidovetaw.pbworks.com/w/file/fetch/144417717/cabrio_washer_error_codes_f5_e3.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8f250818-d4e6-41d0-97a8-80397ce59438/biddeford_electric_blanket_controller_error_message.pdfIn PDF document text
    • http://sufizilofab.pbworks.com/f/how_to_play_among_us_on_pc_for_free_without_downloading.pdfIn PDF document text
    • http://xoxafepapesu.pbworks.com/f/vilub.pdfIn PDF document text
    • http://pagorevet.pbworks.com/w/file/fetch/144473190/what_to_feed_baby_blue_tongue_lizards.pdfIn PDF document text
    • http://xugilip.pbworks.com/f/69582985765.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f138a1a3-2f7c-41ed-8cf7-22ccaed50eb4/asus_xonar_dgx_pcie_5.1_audio_card.pdfIn PDF document text
    • http://gatasulupu.pbworks.com/f/20995163057.pdfIn PDF document text
    • http://lokiboz.pbworks.com/f/unfair_mario_unblocked_games_no_flash.pdfIn PDF document text
    • http://xivoxibuza.pbworks.com/f/50707610472.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_off0000db10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB10 5484 bytes
SHA-256: ef9b63c2548ab73ed8a3e40e54f7951c9b37b9df14f3424346ea9d3043ebed13
font_01_sfnt_off0000ed99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED99 9928 bytes
SHA-256: 91c018333986d34d9ce569048a313725801244e32a8d4ee30aeb03497ab4177e