Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1a90fb8d402b744…

MALICIOUS

PDF

92.7 KB Created: 2021-07-20 17:24:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: bdeaf92efdb243e8706f4448f9f4f2c0 SHA-1: 058806d0e567e48f44ef124beb15b40a210f8cc8 SHA-256: e1a90fb8d402b7447a40afda708529aab5faba793c554f10018202ac3ba3ec31
96 Risk Score

Malware Insights

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

The PDF contains numerous links to other PDF files hosted on various websites, many of which appear to be compromised CMS uploads. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to manipulate search engine results or distribute further payloads. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/aojooka1gcvot134odigdibnnu/zizibiladigogitozemag.pdf In PDF document text
    • http://verynailscm.com/user_img/file/zobewaxetusomemebisixo.pdfIn PDF document text
    • http://timeyear-v.com/userfiles/file/11204476188.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160858fde22f2e---dinapuvarilepamisazuw.pdfIn PDF document text
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/zelajajodiletojuge.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/28643116315.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///11369739018.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/659d734005d44faa5e3cf816da28b671/tigesomatijiwujokexim.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/vmo53u8fi5dque68nusb9v2c8s/wetanazorisowe.pdfIn PDF document text
    • http://ingpiazza.eu/userfiles/files/nosituxisitubirewafozupe.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16073c947df9d9---mudarivoduluk.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/a5719358addeb97ca294f6a00b83fcaf/jolesejasow.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1607670ad14ff0---14432495446.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a16ecd624f2---11836765482.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/cd3f8c6272f7528adecfaf6a7548dbab/jezanipikopapanusodizulin.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/66420312268.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/16083251d6ad38---87438728991.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/34089626556.pdfIn PDF document text
    • https://securitydm.com/slicice/file/wevogolu.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/6daa99f94472cfb54c2d76898164a06a/tekolexef.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/baxazufakulukev.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/vepagumorizulorudatuda.pdfIn PDF document text
    • http://thaiboxes.com/piceditor/file/watatenamu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=questions+to+ask+your+boyfriend+in+spanishPDF 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_off000104b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104B2 11052 bytes
SHA-256: 15cc1baeded41e05e96a386a2ed8cd2fee431b9ec02a34a7b7e10059ae73512e
font_01_sfnt_off00011e51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E51 18332 bytes
SHA-256: c28b92da6acc6dbe51d01ef983fad82cc39318f5f3a021ee4ecf26cdda0b2046
font_02_sfnt_off00014d2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D2D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1