Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1810f4e4cad5947…

MALICIOUS

PDF

87.5 KB Created: 2021-09-05 16:49:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7d57831ac56e54b4b7eff3cf1c6a7833 SHA-1: 49d61c7e6141ede8362bac4b351efdb4f103625d SHA-256: c1810f4e4cad5947f5d3b93f0d8413e061c24e5e241feca4c73dffa2b492e06e
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO abuse. No scripts were extracted, but the PDF structure and URL patterns are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://legend-chang.com/UserFiles/files/5664846103.pdf
    • http://hzdsbg.com/uploadfile/1626098513.pdf
    • https://global-brand.net/userfiles/files/pelixunevu.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160bc4b621447f---41449424048.pdf
    • http://tai-yang.tw/taiyang/upload/file/61357986045.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097636f982b3---9185576754.pdf
    • http://vecsecity.info/editor_up/26102737898.pdf
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc7ca438e3---tuzibepifugunifiwuxadega.pdf
    • http://llux.vn/uploads/files/8339385542.pdf
    • http://casier-a-bouteilles.fr/file/9563084569.pdf
    • https://maugli24.ru/wp-content/plugins/super-forms/uploads/php/files/6c617c895bc0b3f7f61c2f4264436f33/pupemowutunitixukasafiju.pdf
    • http://srutimusic.org/userfiles/file/gusabezinolerurufotiraxov.pdf
    • http://cka-shiba.com/ckfinder/userfiles/files/vovusejosewokakifelo.pdf
    • http://tele-video.ru/upload/files/rojudivajirito.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160cc7ca8c2db9---68309702493.pdf
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/a7355f0a5e9845268f4048d0f7d6f581/rivexiginagozawekugov.pdf
    • http://opuspointpartners.com/ckfinder/userfiles/files/zunezokapeduparisodupekik.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160dbde239fef0---merabev.pdf
    • http://studiosaletta.it/userfiles/files/vubexozapamifude.pdf
    • http://mutitar.com/user_img/files/84484448687.pdf
    • http://urparitet.ru/admin/ckfinder/userfiles/files/88159701328.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=otitis+a+repeticion+en+adultos+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed03.bin
38b14d4cd27e7b45e083878949ada3d0c67a74a30a5981d940e1b07ceda6fae5
pdf-font-stream PDF embedded font (sfnt) at offset 0xED03 10736 bytes
font_01_sfnt_off000105d1.bin
7ba41aa6e84b14a48a230c810670a5bcdaeebd2f10bde349870fc7ee897affea
pdf-font-stream PDF embedded font (sfnt) at offset 0x105D1 19348 bytes
font_02_sfnt_off000136c8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x136C8 16792 bytes