Malicious PDF — malware analysis report

Static analysis result for SHA-256 525156793bdb442c…

MALICIOUS

PDF

84.8 KB Created: 2021-04-02 22:01:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 216982a1b0c079a740874ff9818c9ddd SHA-1: da27f98f87572528b46bd84f78d46a554ab746dd SHA-256: 525156793bdb442caa6bc3107f858f12481aef6a97c940d20609e892951e917e
186 Risk Score

Malware Insights

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

This PDF file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to potentially harmful content. The document body, though heavily obfuscated, appears to be a lure related to educational topics to entice clicks on these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://maypoin.ru/strik?utm_term=quadratic+equation+word+problems+grade+9+with+solution+pdf PDF link annotation
    • https://cdn.sqhk.co/pofevadamem/iahgWig/44682976578.pdfIn PDF document text
    • https://cdn.sqhk.co/figakeves/Igir1C4/classical_piano_sheet_music_for_intermediate.pdfIn PDF document text
    • https://cdn.sqhk.co/susojitigi/jTghvuo/like_a_boss_seth_rogen.pdfIn PDF document text
    • https://cdn.sqhk.co/zetuzire/gd9YrwN/vanudimokugugotunexulej.pdfIn PDF document text
    • https://cdn.sqhk.co/xefijumu/fibnohe/door_kickers_2_mobile.pdfIn PDF document text
    • https://cdn.sqhk.co/podidiwi/a4QxheJ/72725926782.pdfIn PDF document text
    • https://cdn.sqhk.co/kafufojugure/hVgdoha/monkey_bar_fight_game.pdfIn PDF document text
    • https://cdn.sqhk.co/fofotixoz/ijjhihH/robix.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471236/normal_604b539217e53.pdfIn PDF document text
    • http://gujozulogisin.scienceontheweb.net/laxozuged.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460950/normal_60625b26b40f5.pdfIn PDF document text
    • http://radogomi.mygamesonline.org/85860074343.pdfIn PDF document text
    • https://cdn.sqhk.co/vusunuvaka/jekc8ij/wifi_speed_booster_app.pdfIn PDF document text
    • http://pexulisinipev.sportsontheweb.net/btec_level_3_business_book_1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6843e3eb-5573-46e1-90a0-370cfc2b4a0d.filesusr.com/ugd/89b1bc_03c6d27adc8b4e779cb1fae60733e262.pdf?index=trueIn PDF document text
    • http://jaweratiz.atwebpages.com/atomy_company_introduction.pdfIn PDF document text
    • http://xukokumo.myartsonline.com/89534461190.pdfIn PDF document text
    • https://2b08c346-38d8-4763-b559-bb9d4fff2313.filesusr.com/ugd/40c9d6_f6a864770e354921868fcefa55c76af1.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f535.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF535 6144 bytes
SHA-256: 41781d422e65f5fcdab536806d45e3a8ae112ff9056c5b6e03f5153eab887cdf
font_01_sfnt_off000109f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109F5 10984 bytes
SHA-256: 7359fbe2c94780ac3366235b14dd866fded1e1888a990f0168b010edd63aaf20
font_02_sfnt_off00012f87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F87 16260 bytes
SHA-256: bd0256fedb35b197ddd57ea4f5f76f8c23ea94187384d8bc226d5fbbd70a60fe