Malicious PDF — malware analysis report

Static analysis result for SHA-256 db300cbe26cb2506…

MALICIOUS

PDF

81.6 KB Created: 2021-09-18 22:36:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0fe9d5e7518fa06379fdd861cb6362a0 SHA-1: 8b4e1b589c1ac2b15222d0152d97e13ca78edfe8 SHA-256: db300cbe26cb25068cbc5b69dc20d9f348304e2cd19a560d64ee771250cac6ab
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing text but serving as a container for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://philabc.ru/uplcv?utm_term=kinds+of+tone+in+poem PDF link annotation
    • https://hongmao.tw/uploads/files/202109081620044864.pdfIn PDF document text
    • http://irpuyesh.com/cache/fck_files/file/xuvosuvumagurikexeza.pdfIn PDF document text
    • http://nguyenxuanhuong.com/upload/files/83893143975.pdfIn PDF document text
    • http://czechnews.cz/userfiles/files/sisogerofuka.pdfIn PDF document text
    • http://obkladacstvikolar.com/content/19749953189.pdfIn PDF document text
    • http://kodemari.info/data/files/mokotadurubadojewegojug.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f49e362f50---dowelewitomuj.pdfIn PDF document text
    • http://gurukripapublicschool.org/userfiles/file/42296306636.pdfIn PDF document text
    • http://zlzljc.com/uploadfile/file///2021090113121789.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/161339a0a00f5d---kejalubilazedokilin.pdfIn PDF document text
    • http://bojovesporty.cz/userfiles/file/zakazujir.pdfIn PDF document text
    • https://ventadeterrenosagricolas.com/userfiles/file/rudikifoxinumovufa.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/ec0492cc104fd1a8f3ff784d7d102dd7/14848338130.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/48784751888.pdfIn PDF document text
    • https://used-machinetools.ro/app/webroot/files/userfiles/files/3926522676.pdfIn PDF document text
    • http://cyclad.org/UserFiles/file/vixosozelizomasef.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/13721096929.pdfIn PDF document text
    • http://bradzo-ep.com/uploads/files/23494194459.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/g0m641ev9r7tlrck4fplk6umd5/90259307442.pdfIn PDF document text
    • http://landpas.pl/upload/file/topimuvajidumeturorasis.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0adspaa6vg50assupe29cv7l22/48418303046.pdfIn PDF document text
    • http://franzoesischebulldoggen.eu/userfiles/file/45165808016.pdfIn PDF document text
    • http://jnmindia.com/outscapes/admin/ckeditor/uploads/ck/files/19813356334.pdfIn PDF document text
    • http://celyroknaterase.sk/editor_uploads/system/files/kigivupukadegaxava.pdfIn PDF document text
    • http://hungthanhauto.com/luutru/files/22003383702.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://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_off0000d867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD867 10340 bytes
SHA-256: 0a349d1a488f22eb98d4e55764ff1ba493102837848c499e71a6caf1db962a10
font_01_sfnt_off0000efb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C3 19040 bytes
SHA-256: 39dd0a17d733fbd91b1777d881f7a2413095f2e029a91029538e196a826bb5c8