Malicious PDF — malware analysis report

Static analysis result for SHA-256 76cc624c7ba1b461…

MALICIOUS

PDF

94.6 KB Created: 2021-03-14 00:42:31 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-04
MD5: 0fb28817d801646cc6c01e91730c2663 SHA-1: a1cf1ceba455184d47f31be09cda5fde73b76361 SHA-256: 76cc624c7ba1b461b576d34ddbc718decfaf2ed58fa0a8c536435f6815f94d51
186 Risk Score

Malware Insights

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

The sample is a PDF document that contains a large number of external links, identified as a link farm. The primary malicious activity observed is the redirection of users to various external websites, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ClamAV detection and ML classifier further confirm its malicious nature, likely for phishing or SEO spam.

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://midufefew.ru/award?keyword=adenosin+trifosfato+pdf PDF link annotation
    • http://pitikudefojeken.getenjoyment.net/31290740764.pdfIn PDF document text
    • https://rojanebe.weebly.com/uploads/1/3/1/6/131637229/3163933.pdfIn PDF document text
    • https://cdn.sqhk.co/lexaxemiji/igTidha/37079041110.pdfIn PDF document text
    • http://jotusimemirido.sportsontheweb.net/what_is_foil_in_literature.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4377113/normal_600743eb7bab9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369502/normal_60280adf3ccb7.pdfIn PDF document text
    • https://cdn.sqhk.co/makubeku/6icvRGc/benamedokokamet.pdfIn PDF document text
    • https://cdn.sqhk.co/vivepovugeli/1iajhar/8475555504.pdfIn PDF document text
    • http://wopexobow.mywebcommunity.org/is_the_apology_line_podcast_real.pdfIn PDF document text
    • https://wotigutaz.weebly.com/uploads/1/3/4/3/134361511/29302b0.pdfIn PDF document text
    • https://kirewigofe.weebly.com/uploads/1/3/4/3/134382955/dfe2fb.pdfIn PDF document text
    • http://bukobaxaz.getenjoyment.net/small_rainbow_fish_species.pdfIn PDF document text
    • https://dowogejur.weebly.com/uploads/1/3/5/9/135992185/megevedebok.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://c931c956-7f53-4e4e-96dc-27d7f003ba63.filesusr.com/ugd/b80c10_32b9af5e3b30415084fd5b453e024b71.pdf?index=trueIn PDF document text
    • https://41c240d9-b4af-4f88-8fa4-2a41cce3a287.filesusr.com/ugd/01bc73_229557a3275e46ceb6394651c9ddfb17.pdf?index=trueIn PDF document text
    • https://f0198b83-f3fe-41b4-8315-bacd7eabb238.filesusr.com/ugd/2b3f46_8ba4aa04510e4199bd2bf10abad1cb9f.pdf?index=trueIn PDF document text
    • https://c245485c-e1a4-4c5a-9a2a-c465a95e53c8.filesusr.com/ugd/25f824_97fd85774e094e45a576f401fb9ae514.pdf?index=trueIn PDF document text
    • http://fotizojorirepel.onlinewebshop.net/26930650807.pdfIn PDF document text
    • https://29aa9d28-cc9d-45fc-8d86-3718b5881c84.filesusr.com/ugd/74c34a_732477f03344451ab402ed4a1c5a779b.pdf?index=trueIn 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_off00012ff6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FF6 4992 bytes
SHA-256: f4f053ee2dba7b34bcc3b0f3ca83bd5a8556f3f84215ed7fcc1a89c5e66ef6e5
font_01_sfnt_off000140fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140FE 13336 bytes
SHA-256: 7a20eee0d114d2cbcb7c035cb920a96cc59be6ac99ccb8598b23f4e6b278c723