Malicious PDF — malware analysis report

Static analysis result for SHA-256 41a19bd5e3d1f132…

MALICIOUS

PDF

84.1 KB Created: 2021-09-08 05:13:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5b64b3750829972e1a9f628c6cdf4065 SHA-1: 46adcb51fddc19efa9ff9aa918d923456f0d8851 SHA-256: 41a19bd5e3d1f132655a674afe3b270c59f5a502353a835506ed3633a62a7802
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to various websites, including those hosted on compromised WordPress installations. The presence of 'utm_term' parameters suggests an attempt to track user interactions, common in phishing or spam campaigns. No scripts were extracted, and the document body was unreadable, but the heuristic firings strongly indicate a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9946

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://synerhu.ru/uplcv?utm_term=talleres+de+manualidades+faciles+para+ni%C3%B1os PDF link annotation
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202106151845093626.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b19a16868cf---98684011445.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e044fd85f7---2017791233.pdfIn PDF document text
    • http://rlmlaw.com/images/edit_images/file/79921954743.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094ee765b8dc---faxuxi.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf5e7caaad7---jimiwubozoferupenufebeja.pdfIn PDF document text
    • https://www.duffylighting.com/wp-content/plugins/super-forms/uploads/php/files/25c119f278696acf5722c5e4e6f33ee7/61795838698.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a28f5c30c2---95289074436.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aa3caa89715---kesuwelobibapebugiz.pdfIn PDF document text
    • http://chithanhplastics.com/uploads/userfiles/file/xisugiduwil.pdfIn PDF document text
    • http://111-orte.de/testarea/cwsCMSlight/media/files/rovomopikese.pdfIn PDF document text
    • https://b2b-intelligence.it/uploads/file/96345798690.pdfIn PDF document text
    • http://apexnepaltravel.com/userfiles/file/19423933581.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b301674c04---peniladuzopiposawimabenen.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/kuxejiz.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/d51286ad7e75a59d25719c8c14b92dc7/7431014419.pdfIn PDF document text
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rozajutisapod.pdfIn PDF document text
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/it391mhq0g2n8gmijiaovu3k9g/18668218471.pdfIn PDF document text
    • http://prime-standard.com/piceditor/file/dadiwenezasubed.pdfIn PDF document text
    • https://lapakunited.com/contents//files/lotilafonevid.pdfIn PDF document text
    • https://cissud.it/uploads/ck_editor/files/jawalisemesaxedebelufuzo.pdfIn PDF document text
    • http://albertopizzetti.it/userfiles/files/laxatisakofepazixo.pdfIn PDF document text
    • https://euroroma-bg.org/files/file/xupesabuvuno.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160838213d1c4a---donipukapuzolifakit.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f214db11f5---jogevifar.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_off0000dfd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7ED 10952 bytes
SHA-256: 97916a161a5ea64c0ba1e451be0a75bb8f8776270023d848a0ffe1dc12ffce3e
font_02_sfnt_off000110fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110FB 18632 bytes
SHA-256: 216f747bbed3b63ca141dcddea339ed294386772536b6a048621d2480b92e598