Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ff9dfdc137d6398…

MALICIOUS

PDF

78.4 KB Created: 2021-09-01 22:22:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5388612d47cf5cfd46795a0cef5d9755 SHA-1: e1e127a037883cce16a530025becab539b75f5c6 SHA-256: 3ff9dfdc137d6398d4cf21fdb940192f8d68161c600c1a9162e76e380bae895c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised or disposable hosting sites, likely for phishing or malware distribution. The embedded URLs, such as http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160994e56cae06---nubumorisimukiw.pdf, are indicative of this malicious pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073759d537d6---novixowexikopu.pdf In PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/nafesasonel.pdfIn PDF document text
    • http://ankaser.com/userfiles/file/18634026096.pdfIn PDF document text
    • https://likeevent.it/writable/public/userfiles/file/45569693803.pdfIn PDF document text
    • http://cokhiminhhien.com/media/ftp/file/dedova.pdfIn PDF document text
    • http://findmecakes.com/userfiles/files/17288384868.pdfIn PDF document text
    • http://spiregene.com/image/files/20210817_180406.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/c5171a17a8866032a75c91b2cd3022b6/41152219428.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc19f22def0---28793756027.pdfIn PDF document text
    • http://www.ccengis.be/applications/ckeditor/addons/ckeditor/ckfinder/userfiles//files/josar.pdfIn PDF document text
    • https://orldoc.ch/wp-content/plugins/super-forms/uploads/php/files/gpuu79jj4uf1qfj4qv4c5u04f4/jozawibisewisoko.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e6afa165a0e---13025163938.pdfIn PDF document text
    • http://tilestone-pools.com/i/File/6862733220.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160994e56cae06---nubumorisimukiw.pdfIn PDF document text
    • https://kodcomputers.ro/2664/uploads/74129623219.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b50dfa8d95b---49034454943.pdfIn PDF document text
    • http://artechq8.com/beta/uploads/files/33294947947.pdfIn PDF document text
    • http://ilovegabal.net/fckeditor/_upload/file/nadazigutijejufigutewut.pdfIn PDF document text
    • https://ascend.sut.ac.th/ce/2017/src/plugins/ckfinder/userfiles/files/menamuwuto.pdfIn PDF document text
    • https://xanbiente.de/userfiles/file/5758872897.pdfIn PDF document text
    • http://hopkinshigh1988.com/clients/75739/File/56152003995.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607372964474f---6857895164.pdfIn PDF document text
    • http://ge-mak.com/files/bazobefetuwumiwegovowasi.pdfIn PDF document text
    • http://strap.sk/uploads/files/79679002807.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/c5136b428b5d9aace3d2fc5df8280097/jotezesiwik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=from+great+expectations+answer+keyPDF 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_off0000ce11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE11 17032 bytes
SHA-256: c5855c9469e44f24757c037e971f2e0f85b717fd146eaec71af4fe3c733c2446
font_01_sfnt_off0000f9fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FC 11040 bytes
SHA-256: 3f9a8beac19cd5f11fdd3425f322d3f4ab64b8697059f78f83da1bc4c26158dd
font_02_sfnt_off000113cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1