Malicious PDF — malware analysis report

Static analysis result for SHA-256 6555f4f923c7dc4d…

MALICIOUS

PDF

75.9 KB Created: 2021-09-03 04:18:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 273197e495e1c139d54a9d6258d14de4 SHA-1: fb6cf33df938bc9882a3ac8250a09dae662ce0fd SHA-256: 6555f4f923c7dc4d2b02bff509fe245531f9a6adb7a271686695ec3252abb100
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, indicating malicious intent. It contains numerous links to external websites, many of which appear to be part of a link farm hosted on compromised or disposable domains. The primary purpose seems to be directing users to these sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://infrive.ru/uplcv?utm_term=free+kindergarten+halloween+worksheets+printable PDF link annotation
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/f0b4e86f9771739c39c533f8ea22cbeb/kefojokutali.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/t429hqvne2fteo35ahknmu5reu/81434287310.pdfIn PDF document text
    • http://dotbamboo.com/file_media/file_image/file/judolenibetomiwubusin.pdfIn PDF document text
    • https://przygodanaukrainie.pl/admin/ckfinder/userfiles/files/42594697735.pdfIn PDF document text
    • https://bloomlight.pl/_bloom/file/vulagoranam.pdfIn PDF document text
    • https://nieruchomoscikomercyjne.co/files/file/purawe.pdfIn PDF document text
    • https://denimder.org/resimler/files/wijeb.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160dcd5542158b---33580454204.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609c74a6a41de---bagabum.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acf71b92383---jubigu.pdfIn PDF document text
    • http://ledseoul.com/userData/board/file/gitos.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/56238506371.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/67e5ed7969386c2e03e07e7105154752/gedubopaf.pdfIn PDF document text
    • http://gmkms.net/upfile_editor/2021/files/wododuzakekukoselevinev.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/64b1o89ndrugq9s9o9s6gk5olh/70258039966.pdfIn PDF document text
    • http://hiroi-es.info/yamituki-n/uploads/files/pulojajawok.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/22456172194.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/160f68a27e0254---29088191814.pdfIn PDF document text
    • https://xulynuocphangiathinh.vn/images/pic/file/bitovuxosade.pdfIn PDF document text
    • http://studiovalentini.eu/userfiles/files/12651406010.pdfIn PDF document text
    • https://zohopin.com/calisma2/files/uploads/7704213063.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b51776bb8b6---85061541731.pdfIn PDF document text
    • https://takeorders.online/wp-content/plugins/super-forms/uploads/php/files/t8beni2gsklqbthk2314rmcqgt/buvanopatinonosejopa.pdfIn PDF document text
    • https://poojaindiangrill.com/nbloom/fckuploads/file/virizidikivumilejamesuri.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_off0000c633.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC633 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE4A 10964 bytes
SHA-256: 114efb8a15e1d723c8a4e6bded8e36f08a79c251c2f726b68bdac3c8cb197b85
font_02_sfnt_off0000f73f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF73F 16364 bytes
SHA-256: bbc4c7fbb848f69b7247678989a4ba8dcc09257339a696c06f94811895b25c29