Malicious PDF — malware analysis report

Static analysis result for SHA-256 c809d0ad9e587c6c…

MALICIOUS

PDF

73.7 KB Created: 2021-05-26 17:29:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 8eb3ff324e9c9dbe7ebea2998aa00d20 SHA-1: 5ef783999017f392dad6de3e481a1e15c2d89e10 SHA-256: c809d0ad9e587c6c96d710acb786c0551fa60a045f0412233c7091f85f9dee07
126 Risk Score

Malware Insights

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

This PDF file contains a large number of external links, many pointing to disposable hosting services. The heuristic 'PDF_SEO_LINK_FARM' indicates a link farm, suggesting the document's primary purpose is to manipulate search engine results or redirect users to potentially malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

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://jottigo.ru/strik?utm_term=gerund+worksheet+with+answer+key PDF link annotation
    • https://nunewefumeko.weebly.com/uploads/1/3/4/3/134307525/5391832.pdfIn PDF document text
    • https://jilukixewe.weebly.com/uploads/1/3/4/0/134042659/a4cd0c1.pdfIn PDF document text
    • https://mogewojelepa.weebly.com/uploads/1/3/4/6/134681452/suxisuxefasowale.pdfIn PDF document text
    • https://lerorenoj.weebly.com/uploads/1/3/5/3/135390996/64a8236df305.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4453885/normal_5ff868f90854f.pdfIn PDF document text
    • https://lemuvizavo.weebly.com/uploads/1/3/2/6/132682731/ropujan.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369316/normal_603e4b077116d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408720/normal_6063ce58d8b79.pdfIn PDF document text
    • https://saripubisopa.weebly.com/uploads/1/3/5/3/135322362/2699426.pdfIn PDF document text
    • https://mokufanogokotim.weebly.com/uploads/1/3/1/4/131406807/f269e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375696/normal_60135b774059f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445104/normal_60293c5c0052b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368979/normal_5ff9f4161f316.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381544/normal_5fe8f9a5105ef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367644/normal_606e372f8c64a.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/28b9f841-3b44-4cbd-b436-ee03f8da5c55/sirowelewiruvo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eb7befcd-a4a4-4ae6-8779-411928428c33/kanunogutaxidovob.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0e8b21b0-9f58-4940-a584-ac6b8af0785c/vobujavajemutevuv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8ab30d7e-2732-41a7-8336-0d8eb38cd1b0/infantino_flip_4-in-1_convertible_carrier_grey.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/edbd5c0c-40bc-49f6-a487-6df5f39b1418/washington_post_games_page.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_off0000e194.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE194 5172 bytes
SHA-256: ce353d1dac35e325d8561abea7a2d26cb75589c03f36aafd11501780c7a3a689
font_01_sfnt_off0000f341.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF341 11256 bytes
SHA-256: f93d884b6408e9c966ce73ea0a35567af3e30a4d3ad4ceaed16b2ba421f01922