Malicious PDF — malware analysis report

Static analysis result for SHA-256 50e11d43f56f90e3…

MALICIOUS

PDF

87.5 KB Created: 2021-09-17 11:26:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0263841c3268a8feeb17e7f9ee0a6153 SHA-1: 947eae4ef56243c01acb4151c2d2bc1cd90d1fd0 SHA-256: 50e11d43f56f90e3a274b2e73a0e6d2ee47d1604c734456a26f32ca167d91ae0
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to external sites, some hosted on compromised CMS platforms. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://academiapreprod.riportico.com/userfiles/files/73022790452.pdf In PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16132b2d5f2cb7---67380829654.pdfIn PDF document text
    • https://rent-1.es/ckfinder/userfiles/files/5125468185.pdfIn PDF document text
    • http://hunicorn.hu/userfiles/file/89539928002.pdfIn PDF document text
    • http://greenglobepms.com/uploads/25530374102.pdfIn PDF document text
    • https://stka.gr/ckfinder/userfiles/files/zaxubuno.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/da5e44f0e5f8925096701e9af2f914f7/pulovesibe.pdfIn PDF document text
    • http://www.salpasafarit.fi/tiedostot/files/29939542235.pdfIn PDF document text
    • http://tnslib.tools/userfiles/files/37516773938.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/77089313429.pdfIn PDF document text
    • https://ku4ysk-9lgp4y.com/contents/files/83717927999.pdfIn PDF document text
    • https://weyergans-hcc.lv/userfiles/file/rokikapewufe.pdfIn PDF document text
    • http://www.psyforyou.nl/upload/fckeditor/file/30909956988.pdfIn PDF document text
    • http://benjapakee.net/UserFiles/File/goveluboxamejilib.pdfIn PDF document text
    • http://syntrend.critical.tw/upload/files/94697209605.pdfIn PDF document text
    • https://chulintemple.org/CKEdit/upload/files/13732518152.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/jududex.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140bc0523176---57947370864.pdfIn PDF document text
    • https://alley.52886.tw/uploads/files/82482061474.pdfIn PDF document text
    • http://cu-mbc.com/ckfinder/userfiles/files/14338063786.pdfIn PDF document text
    • http://showpalmedical.com/userfiles/fesasisinisivenavibejafof.pdfIn PDF document text
    • https://indirimlipin.com/calisma2/files/uploads/dexuwepuxogolebaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=notes+of+e+chordPDF 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_off0000f1cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1CF 10148 bytes
SHA-256: 8eb0b7bf7f74903eac9ef8bcc0b2accf07f04648daebd35a2b68f6be75b96430
font_01_sfnt_off000108a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A5 18480 bytes
SHA-256: bc5858054ccea3babc18292f345a89565e2d9c7d6f9fd337a82b9e190ae1b336
font_02_sfnt_off000138b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1