Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b7d4f2933ad42f…

MALICIOUS

PDF

75.2 KB Created: 2021-06-08 05:56:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 0915f36b80d80b7c3d8d7048be219388 SHA-1: b46852b9b3f9263ca4c89eac0a1bcb88fdf9e3e9 SHA-256: 83b7d4f2933ad42f2e7cd41e68ae109e8540dedbd3cd93712cba1ffd76d83970
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or malware distribution attempt. It contains numerous links, with a primary external URI pointing to a URL that appears to be part of a link farm designed to redirect users. The document body, though heavily obfuscated, suggests a lure related to free crochet patterns for babies, which is likely a pretext to drive users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • 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://krisoc.ru/pbw?utm_term=colchas+de+ganchillo+para+bebes+patrones+gratis PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4409093/normal_602470450a060.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501233/normal_604504adad056.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405194/normal_6037a35b7a633.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4506170/normal_60421dbc78098.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4458854/normal_5fce867e9fea6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426422/normal_5fd9b640b7ce1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445754/normal_5ff5ca53b6940.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365552/normal_6046eb9e7fced.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4482402/normal_60084006caa90.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444386/normal_602406ce98270.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/9de0df50-242b-41aa-ab07-82b6a43a5a8b/augusto_cury_nunca_desista_de_seus_sonhos_baixar.pdfIn PDF document text
    • http://vedufid.pbworks.com/w/file/fetch/144510672/a_practical_english_grammar_exercises_1_answers.pdfIn PDF document text
    • http://mevuteled.pbworks.com/w/file/fetch/144617841/62935269129.pdfIn PDF document text
    • http://pijipusap.pbworks.com/w/file/fetch/144620745/what_is_solution_focused_brief_therapy_used_for.pdfIn PDF document text
    • http://pidexuxok.pbworks.com/f/59269988520.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cb49ad62-355c-479a-ab04-1ca29b948cc9/krups_egg_cooker_amazon.pdfIn PDF document text
    • http://mifimoruzuwo.pbworks.com/w/file/fetch/144833157/85618762249.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b6563fc3-d3a7-4391-a65e-bdf1546e5ed1/pokemon_ruby_rare_candy_cheat_code_for_android.pdfIn PDF document text
    • http://bipuwetek.pbworks.com/f/biwozaw.pdfIn PDF document text
    • http://xixokuzujoz.pbworks.com/f/66734991673.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e0c97bf7-c6a5-42e8-a667-ed06fb0a71ad/who_should_have_played_sookie_stackhouse.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c178671-85d5-4bc5-9c86-fe96e43e12dc/76307385151.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc949978-7840-4018-8801-78910d998320/19527730571.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6aa1868a-e538-45d2-aa99-c5625fdee114/14955821553.pdfIn PDF document text
    • http://duziruromeja.pbworks.com/w/file/fetch/144498954/is_doom_slayers_collection_worth_it.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1fd00cf5-ee63-49c7-8cd4-24c5292cbc5d/arris_tm502g_speed.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_off0000e6a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6A8 5380 bytes
SHA-256: 125525b05a56383cdb7d55ec3095338f901cca062953ebcdb90316a9be5ced78
font_01_sfnt_off0000f8dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8DC 11180 bytes
SHA-256: f636e117878109f71b24bc7c05b5fb529806a9bbf55a608d6eb61d4a94e8a308