Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3b91221f6adf8bc…

MALICIOUS

PDF

94.4 KB Created: 2021-09-01 13:03:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 343e86f848515c511fe9943a85d90de3 SHA-1: 79fa4cd16d9214b950f3297a3122f4124817ffea SHA-256: b3b91221f6adf8bc67413fd09fe6b8e331a30d03785fcaa4f043b5e027394fa1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous URLs, many of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is designed to manipulate search engine results or redirect users through a series of disposable domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ctapigroup3.com/contents//files/zimun.pdf In PDF document text
    • http://studiogiovannone.com/userfiles/files/93895696106.pdfIn PDF document text
    • https://hostingalani.com/calisma2/files/uploads/80371625121.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160ed13c0ba569---10996382540.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/h2qjsjveujf86et4g2e0h4js3q/davadoziwatijiw.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160b0d8d7eba84---refenigutotov.pdfIn PDF document text
    • http://myslizdrave.com/soubory/4301055589.pdfIn PDF document text
    • https://sananselmo.com/wysiwygfiles/file/tebuvonutunaga.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ff3d50b47---73216326758.pdfIn PDF document text
    • http://runbo.net/upfiles/files/16292919983430.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/ab44a221e540df41815fe6a3441e668c/desabefowoxuwefugukazutak.pdfIn PDF document text
    • https://xtrafitcoaching.com/www/images/files/977710232.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/e607b39c8ab85a421d835dd202704b37/debijadaxuduwu.pdfIn PDF document text
    • http://anindecor.pl/files/file/185397990.pdfIn PDF document text
    • https://tlpnw.com/wp-content/plugins/super-forms/uploads/php/files/2386305fa46b36288ad43e92374801ef/73648536768.pdfIn PDF document text
    • http://centrostudiapulia.it/files/files/nadokevajawa.pdfIn PDF document text
    • http://deurenhanger.nl/userfiles/file/paxobenekikebaf.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/202181723308711.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c1fe805f58---6514658009.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16118414a77609---komux.pdfIn PDF document text
    • https://tappowine.com/file/vosefadumajafetajodi.pdfIn PDF document text
    • https://zahnersatz.pl/userfiles/files/vonorukuberozopewozafozir.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/1474335569.pdfIn PDF document text
    • http://brlairport.com/images/file/80651424895.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/6096705900.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=examples+of+neocolonialismPDF 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_off00010c05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C05 10528 bytes
SHA-256: eeee65b6d15c51898f5cc36a565997fef89f6a68d3abdd0079cfee773f0b1f29
font_01_sfnt_off000123f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123F9 18212 bytes
SHA-256: ac1128aefb0b1346c813d211ca6af5ae2b12ddcabc2fea8a0c208da926e9ced5
font_02_sfnt_off00015382.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15382 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1