Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1692f24c40c37b3…

MALICIOUS

PDF

87.9 KB Created: 2021-09-02 19:19:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b3e232ec8cf7bba7614c0a866fdf0501 SHA-1: ca32f336660ef8eb5cbdc64ccd020e7d7a501081 SHA-256: a1692f24c40c37b3b540ed3dbae95cd6c1cb62ee20312462f4f024b254ddc884
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous external URIs pointing to various websites, many of which are hosted on compromised CMS uploads or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://xn--fiqa735be48e.com/upload/files/vanusepavofiwosokab.pdf In PDF document text
    • http://shihtzufurbabies.net/clients/d/d3/d383cf0c90cf2d2391705d5438694b4c/File/bexenus.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/160b755ceb9ae1---zawul.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/8008276173.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-8-23/20210823183600876675.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160aff49ea99e9---rozujoxenumafulixajog.pdfIn PDF document text
    • https://ilc.ua/wp-content/plugins/super-forms/uploads/php/files/0nc7uiiq0cu71gm9dcfe8rj7r5/romolomokub.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/nenumawujomobumobo.pdfIn PDF document text
    • http://tsrmmessina.it/userfiles/files/talodusabewugekoxozisex.pdfIn PDF document text
    • http://lucann.com/Upload/file/lodetapol.pdfIn PDF document text
    • http://ksnjl.com/userfiles/files/34786820164.pdfIn PDF document text
    • http://www.iece.in/userfiles/file/6223048790.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1607b352b74670---8505130159.pdfIn PDF document text
    • http://decamiones.com/userfiles/file/mekegodovuguxevuwopek.pdfIn PDF document text
    • https://baglab.pl/galeria/file/53395968437.pdfIn PDF document text
    • http://lauraestetica.com/userfiles/files/79728148040.pdfIn PDF document text
    • https://soudurelausiere.ca/upload/editor/file/14798727531.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1df353b66---38557667671.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/989f24391ea8dd3c7baee23eea917350/56543098060.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/d36f9ee81b7b2bf07cb7956f8e547382/30969578314.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/2042e20826b2a14b672dfdb4cd71ef8c/gikaxatevetetana.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/01s4pa6v06r8vuv421vq43o4vi/wimuzalonabina.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=nmr+solved+problems+pdfPDF 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_off0000f038.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF038 10388 bytes
SHA-256: c15c776fa2eb926890f6e71af3debb9471e7f46e19f4810607f23d63fa3965ef
font_01_sfnt_off00010775.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10775 19380 bytes
SHA-256: aa82f41b47d9640f02cb6696ebaaf63856c2577ca6f908c6bed3dbad7fbd0d23
font_02_sfnt_off00013a1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1