Malicious PDF — malware analysis report

Static analysis result for SHA-256 3decd6437b6202e5…

MALICIOUS

PDF

77.1 KB Created: 2021-04-02 21:40:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-20
MD5: 2572244a07a7489b766f8ae73faa54d9 SHA-1: ff1c30ebceb942968ff039d3a5873de2927f0137 SHA-256: 3decd6437b6202e5ef39ec4afe99c7f9a4484507e3ee3fc555fb2cd81dc33b54
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many hosted on disposable domains, suggesting a link farm or SEO spam operation. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, hinting at its generation method and potential use in distributing malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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 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://jumiwimov.ru/award?keyword=air+water+and+noise+pollution+pdf PDF link annotation
    • https://cdn.sqhk.co/woteruzid/iaibBjg/99005778436.pdfIn PDF document text
    • https://cdn.sqhk.co/lelogivotosu/3b71hif/war_robots_pc_cheat_engine.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367273/normal_604150307dcc4.pdfIn PDF document text
    • https://cdn.sqhk.co/pidagasew/mjbiehc/48035002665.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476924/normal_6058f82fab261.pdfIn PDF document text
    • https://cdn.sqhk.co/nugofonavuf/yjiLMjf/green_party_election_2016.pdfIn PDF document text
    • https://cdn.sqhk.co/texirova/eLhjVhc/dunk_lords_achievements.pdfIn PDF document text
    • https://mobonojijokatu.weebly.com/uploads/1/3/4/3/134320628/wixepodumi-kiwoxoku-sisedipoxulad-gameripoxo.pdfIn PDF document text
    • http://taxokijoba.sportsontheweb.net/zojirushi_bread_maker_virtuoso_plus_recipes.pdfIn PDF document text
    • https://jeziwirumefije.weebly.com/uploads/1/3/4/6/134670599/2685243.pdfIn PDF document text
    • https://cdn.sqhk.co/febapaji/jd7gih3/russia_penalty_world_championship_2018_lagged.pdfIn PDF document text
    • http://bixaxivajujojar.mypressonline.com/williams_wall_heater.pdfIn PDF document text
    • https://cdn.sqhk.co/kobewudojuvo/hEHll95/zakunewitozojerikap.pdfIn PDF document text
    • https://voxudipuxun.weebly.com/uploads/1/3/5/3/135319737/3256394.pdfIn PDF document text
    • https://cdn.sqhk.co/bitowiso/iugiFcv/35187004009.pdfIn PDF document text
    • https://dawawasokiju.weebly.com/uploads/1/3/1/4/131408838/lunukofu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449614/normal_604dd7229160d.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://e691ad07-92dc-45fa-af10-8929b4045ede.filesusr.com/ugd/87b9a8_59d20b61bcff46288a0e91d98303962d.pdf?index=trueIn PDF document text
    • http://zovibeviniga.myartsonline.com/27389478208.pdfIn PDF document text
    • https://064d663d-f6b2-44cf-a6ad-083da5f315e5.filesusr.com/ugd/77eba6_169edb02463f4fba8711b53d09421dff.pdf?index=trueIn PDF document text
    • https://86a9da1b-0b57-4b35-a77a-523886b904cd.filesusr.com/ugd/0d9a50_d103cbecd48e4f49be01f9dcefd529dd.pdf?index=trueIn PDF document text
    • https://medlineplus.gov/airpollution.htmlIn 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_off0000f221.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF221 5116 bytes
SHA-256: afef6eac6eea9c881cee3de74b66a4179e2a70839b074f7ae4bd6b29628a0374
font_01_sfnt_off000103af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103AF 10368 bytes
SHA-256: 51c56956444e856fc26e039bbbde1631d79007244341ab2aa35ec8664c767e9f