Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4f89bb9611d4c43…

MALICIOUS

PDF

75.1 KB Created: 2021-09-18 02:52:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b96f697fc8ebcdee8f362611c2fd8359 SHA-1: 71e755a4b9057d965d347d0a82b60755e379eb15 SHA-256: f4f89bb9611d4c43dd8ecc77fc84d0cc8579d1dcc4e83a343ac939388a20f964
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by multiple heuristics and an ML classifier. It contains numerous embedded URLs, many of which point to suspicious domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for a large number of links, a common tactic in phishing campaigns. While no scripts were explicitly extracted, the PDF structure and embedded URLs strongly suggest an intent to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://imbirimbir.ru/files/zusofepefe.pdf In PDF document text
    • https://gaziemirkentkonseyi.com/upload/files/rikij.pdfIn PDF document text
    • http://consol.hu/images/uploadedimages/file/62275220196.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/18237609587.pdfIn PDF document text
    • https://a-guskov.ru/uploads/files/lijino.pdfIn PDF document text
    • https://irrisyst.eu/files/file/79364641728.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/28602531385.pdfIn PDF document text
    • http://werkschoenenverkoop.nl/images/docman/files/zitezesuretexowagori.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-13/20210913050305659153.pdfIn PDF document text
    • http://gocep.org/data/userfiles/files/xinotukuvat.pdfIn PDF document text
    • https://ratoempat.com/contents/files/nozamis.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135aa9cbe4a9---57417865189.pdfIn PDF document text
    • http://dayou.tw/uploadpic/files/202109020530291617.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/2889c155adfd68fc80f12de95062e139/vetatawilelusoxakogurija.pdfIn PDF document text
    • http://japan-railpass.info/images/blog/file/nerarawavorororemo.pdfIn PDF document text
    • https://learnrkb.jugalbandiresearch.com/ckfinder/userfiles/files/80602110544.pdfIn PDF document text
    • http://vietsonplastic.com/uploads/userfiles/file/rutebe.pdfIn PDF document text
    • http://fkhd.cz/data/img/67006640277.pdfIn PDF document text
    • http://wwm-quanta.com/upload/files/24996095409.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/57354171766.pdfIn PDF document text
    • http://webinaris.blog/ckfinder/userfiles/publics/files/35928358169.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/botes.pdfIn PDF document text
    • http://aksusu.com/upload/files/zegewigedus.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/54137136206.pdfIn PDF document text
    • http://kelsenator.com/userimages/25581790280.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=live+tv+hd+streamz+apkPDF link annotation
    • 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://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_off0000c474.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC474 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC8B 10564 bytes
SHA-256: 7e43983608f4300fdc6da65493abbf429362bdc051cccf768987de23a05d6205
font_02_sfnt_off0000f4b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B4 16576 bytes
SHA-256: f02387ebb9ab0b7ebf5834daa6f62c6413241b501262638d06a165ef8264655e