Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81020adf32025d2…

MALICIOUS

PDF

75.8 KB Created: 2021-06-06 18:33:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: a952d0a04dfe997a521fb3fa3b473530 SHA-1: c976d916edeb44eb0c51d522cfb0bef9446b2e27 SHA-256: f81020adf32025d26fef8b945f1e444d6e3251c5fd639aa4f424a6a0a552da4b
136 Risk Score

Malware Insights

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

The PDF contains heuristics indicating it's a phishing lure, specifically using an image to redirect users to a URL that claims to offer free worksheets. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the PDF structure and embedded URI point towards a phishing campaign, likely using a social engineering pretext to trick users into visiting a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://crewmak.ru/pbw?utm_term=articles+a+an+the+worksheets+for+grade+4 PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4370791/normal_60078fe8475fe.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4410983/normal_60b01542482ce.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408864/normal_5fe3e34f8d259.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383568/normal_6062f010045cd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418170/normal_6014868c6f073.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375200/normal_5fddb640e688d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421040/normal_601c986c8d920.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4373241/normal_60b5d95cd315f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486220/normal_601449632ab44.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467032/normal_6034eb88e3bc5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482619/normal_602ec724afd19.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/c76578a7-6e53-465c-9cdc-f7e3bdca7676/guia_ceneval_bachillerato_2020_gratis.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4dd0c1cd-7ee5-4ab2-b4f0-8dba08c236ae/2007_harley_davidson_sportster_883_owners_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/058ac453-cfad-4666-b9cc-b29f4b2eea4b/61880041791.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a3ca7c20-c29f-48c3-850d-1ccc20ed8c46/how_do_i_add_disney_plus_to_my_apple_tv_3rd_generation.pdfIn PDF document text
    • http://sekodegaxex.pbworks.com/f/89935886793.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f201eabb-4bdf-4695-bcb4-49696cbfec0d/69893188890.pdfIn PDF document text
    • http://nanefumipopo.pbworks.com/w/file/fetch/144501657/3675983283.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e1d59436-152e-40be-961a-b47fabfc6457/partes_del_poema_para_nios_de_primaria.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/df44e23a-5054-4997-9299-beab59e7ec18/fifty_shades_darker_movie_songs_320kbps_download.pdfIn PDF document text
    • http://wemilamozede.pbworks.com/w/file/fetch/144550230/chronic_traumatic_encephalopathy_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7492b05a-e893-4ba4-8e86-7bc7a9202c80/21213966852.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ea48167c-7643-4bcb-9cc1-e571037311d5/67601823962.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_off0000ea21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA21 5516 bytes
SHA-256: 6eaff0055f255e8e510becc8164c44f9f1649967cd192c2def4ab5dab03b0e32
font_01_sfnt_off0000fcf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCF6 10792 bytes
SHA-256: ab4c3f97f8ca9bf9dd7f3dd452fea746cf1324d13080881da7384851312e9237