Malicious PDF — malware analysis report

Static analysis result for SHA-256 13f25a9813b7180c…

MALICIOUS

PDF

76.5 KB Created: 2021-09-08 06:21:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 317b604623e3297e78b0136a5d16b0da SHA-1: a4ac960ca949f47b1804cf76c4949ff50f3e4f9e SHA-256: 13f25a9813b7180cf313e5939f1a1e933d74b76606d97c505c7e6ce159203808
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting. These links likely serve as lures for phishing attacks or to distribute further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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 http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/16074472c238c7---jiret.pdf In PDF document text
    • http://schodylux.pl/userfiles/file/tawavet.pdfIn PDF document text
    • https://abe-rdc.com/userfiles/file/46381318027.pdfIn PDF document text
    • http://hotelbelleepoque.bg/userfiles/file/56218841353.pdfIn PDF document text
    • http://fisioterapiasuzzara.it/userfiles/files/filesosu.pdfIn PDF document text
    • https://remont-bez-zabot.ru/files/file/28661306048.pdfIn PDF document text
    • http://famillespourstarlight.com/clients/a/a9/a9b42c05011d3bb27e7f7ec2ed30324f/File/23903511486.pdfIn PDF document text
    • http://sshs61.com/clients/6/60/60e739d5a8cf4a6710e4f064fd99417d/File/37466988498.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/f41b79583f66be5ab859bde34b8f3756/89618753036.pdfIn PDF document text
    • http://npi-management.org/ressource/site-image/files/memodov.pdfIn PDF document text
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/rotogn8c7gt861m74qf7j8u992/12263233566.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160765bd474ce6---jagigafefomefebinugelu.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086d70286678---lapavon.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/953cpu8rbo214v6l9ib3r1n7t9/rebukaxebamurubovalenomut.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1613133dfaed3e---51899622534.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e1dccf41f---zavaruweta.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/6b987561788742b35baabc9299f710fe/28331252688.pdfIn PDF document text
    • http://sutphinsgermanshepherds.com/clients/21958/File/25359272062.pdfIn PDF document text
    • https://absoluteanytime.com/media_file/files/files/dukowunegarodepamisoxova.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b1fb5b91743---69648570452.pdfIn PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f1390094723---31691125029.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/47c8cf4cbefbbecf31e1bb99c107e84e/rusekuzawobab.pdfIn PDF document text
    • https://artlabjo.com/userfiles/file/64322436066.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/3drjngljb8br0850vi64gi5c44/14867770704.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/16099c81aabadf---71090569605.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=irregular+imperfect+verbs+spanish+worksheetPDF 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_off0000c13f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC13F 11360 bytes
SHA-256: 9f60c4d9d470559f3f71a9d18a6f4795ba18ab4c316d86cce9020682e8433ff6
font_01_sfnt_off0000dba4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA4 18704 bytes
SHA-256: 52bed1de335a9a13c2d9de0514d3ae27095170c58147a15dd243585fdb2175d6
font_02_sfnt_off00010b98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1