Malicious PDF — malware analysis report

Static analysis result for SHA-256 857b15bccbc463f5…

MALICIOUS

PDF

96.5 KB Created: 2021-04-07 11:08:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 5bdf57f8c84e40a7aee36fa46e5ca535 SHA-1: 5ba8f298aa8644c0b4a5854cb240a030d46bbc2c SHA-256: 857b15bccbc463f59e836348131ae44fac876f6b49932f6ad9438b0ddeabc69c
126 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and 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 0.9998

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://vilenefex.ru/strik?utm_term=can+you+be+allergic+to+pizza+rolls+in+the+fridge PDF link annotation
    • http://fipizilemuwob.medianewsonline.com/50824863752.pdfIn PDF document text
    • https://cdn.sqhk.co/regavebike/CWjjbjd/craigslist_ny_cars_by_owner_staten_island.pdfIn PDF document text
    • http://ledozikatiresev.scienceontheweb.net/how_to_clean_coils_on_dometic_rv_air_conditioner.pdfIn PDF document text
    • http://rixuliketasaban.mywebcommunity.org/boston_bruins_schedule_2020_19.pdfIn PDF document text
    • http://rejawulomov.mywebcommunity.org/cherokee_paul_mcdonald_a_view_from_the_bridge.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470387/normal_5fdc05ff1db70.pdfIn PDF document text
    • https://cdn.sqhk.co/rozamulev/gMzdhec/65045500666.pdfIn PDF document text
    • http://sunugukumota.getenjoyment.net/899794622.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468831/normal_605d14c261727.pdfIn PDF document text
    • http://hurleyshamburgers.com/kitchenaid_pro_600_series_6_quart_bowl-lift_stand_mixer_-_aqua_skyx2c6f.pdfIn PDF document text
    • http://housefashion.ru/12_week_year_study_guidedovlu.pdfIn PDF document text
    • https://cdn.sqhk.co/feketukadoz/bjjmz4C/46078370614.pdfIn PDF document text
    • http://mavaxur.mywebcommunity.org/cards_against_humanity_expansion_download.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://ledufowi.myartsonline.com/60531315924.pdfIn PDF document text
    • https://s3.amazonaws.com/tapelu/alif_laila_bangla.pdfIn PDF document text
    • https://s3.amazonaws.com/rejiner/11594679968.pdfIn PDF document text
    • https://s3.amazonaws.com/fonazuzixagizir/pefal.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_off0001360b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1360B 5616 bytes
SHA-256: 5cc5309358f660beff4d13e72152882081cf7394c6b2298fa3bcf6375ed7618e
font_01_sfnt_off0001492d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1492D 12316 bytes
SHA-256: e594871fdf7185c299de72e4d4cad66d43be37d184d2605ab9e08b1bece6dd77