Malicious PDF — malware analysis report

Static analysis result for SHA-256 5523d8c78b9c8e42…

MALICIOUS

PDF

71.4 KB Created: 2021-03-24 17:46:51 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 8f5b7ed612ff98be49340ecd6e398379 SHA-1: 545b373df48974ebdefa876cf0fb5ce28c761578 SHA-256: 5523d8c78b9c8e42a159db39504e33955e48e23d3652c1ab6f11508519018c3d
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to disposable hosting, and one external URI that appears to be part of a link farm. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of numerous links indicates an attempt to direct users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://kuzutuzo.ru/award?keyword=comparative+adjectives+and+adverbs+worksheets+pdf PDF link annotation
    • http://jabofedu.sportsontheweb.net/sepetuxatolavif.pdfIn PDF document text
    • https://kusejatakobex.weebly.com/uploads/1/3/1/4/131438299/wibar.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467577/normal_5fe40db0b2d55.pdfIn PDF document text
    • http://lapitubemexidi.mywebcommunity.org/6726114107.pdfIn PDF document text
    • https://cdn.sqhk.co/voduzetefir/jfihhgr/all_zombie_killing_simulator_codes.pdfIn PDF document text
    • http://wotaged.22web.org/17200498533.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382406/normal_60482a1ddb017.pdfIn PDF document text
    • https://voranafirodibug.weebly.com/uploads/1/3/2/6/132696030/banewemeg_lejovupetogigi_sizutudosog.pdfIn PDF document text
    • https://cdn.sqhk.co/xiwogoxozoxi/oUdidFn/recorder_notes_chart_with_letters.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404755/normal_6005a1df007d7.pdfIn PDF document text
    • http://jawixogu.mygamesonline.org/qu_significa_dominio_en_matemticas.pdfIn PDF document text
    • https://ribelogexarov.weebly.com/uploads/1/3/4/5/134500322/taronetadisevipo.pdfIn PDF document text
    • https://lidubudizut.weebly.com/uploads/1/3/2/8/132815063/nojexesasu_voboziguja_sulejitasoda_vegoj.pdfIn PDF document text
    • http://rixuliketasaban.mywebcommunity.org/children_s_haggadah.pdfIn PDF document text
    • https://cdn.sqhk.co/zivuwimavez/hhXid9P/60914428839.pdfIn PDF document text
    • https://cdn.sqhk.co/goluxewimabu/jhu2dBs/67529960648.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369143/normal_5fdb98ce989df.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://nufiwimuzobo.onlinewebshop.net/walgreens_automatic_wrist_blood_pressure_monitor_reviews.pdfIn PDF document text
    • http://fiforeru.atwebpages.com/how_to_use_a_steamer_bamboo.pdfIn PDF document text
    • http://tiwatimab.atwebpages.com/58236891393.pdfIn PDF document text
    • http://sebokegekesuded.atwebpages.com/mist_fmge_notes.pdfIn PDF document text
    • http://bedafemupoba.rf.gd/cdigo_de_tica_trabajo_social_chile_2019.pdfIn PDF document text
    • http://kenavegolixase.epizy.com/ncert_biology_textbook.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c954.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC954 5608 bytes
SHA-256: 3a9c8cb73214666ffadb675b621b2ed0396babbc454d0c2f41a1f46e2630c646
font_01_sfnt_off0000dc48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC48 10504 bytes
SHA-256: fc21808c347983ff56fb82417e7e864f9600d51b5ab2c95bc49873b4ede21c37
font_02_sfnt_off0000ffcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFCC 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3