Malicious PDF — malware analysis report

Static analysis result for SHA-256 888804f1ad1daf05…

MALICIOUS

PDF

76.2 KB Created: 2021-09-21 20:42:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 87554a9aa3384ec78d81d288efb2d84d SHA-1: 661661a81acdb5ea3bfbc76e8618047039902b19 SHA-256: 888804f1ad1daf059ad2ce8dbf7cdebe034a8a48f8ce634b579214db683093f6
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery through these links. The presence of multiple compromised CMS upload links and SEO-disposable link farm heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://dietetyka-24.pl/images/files/16890796604.pdf In PDF document text
    • http://clerus.hu/files/file/43939263579.pdfIn PDF document text
    • https://98ing.com/upload/ck/files/20210911_202613.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2d44b32c7---tonazekiwuvijonedoviperu.pdfIn PDF document text
    • http://jdjcnc.com/upfolder/e/files/20210921154902.pdfIn PDF document text
    • http://omnoiptv.com/outscapes/admin/ckeditor/uploads/ck/files/wugosegejinugaj.pdfIn PDF document text
    • http://alltechsro.cz/files/93001750268.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140ed7a05792---10474999141.pdfIn PDF document text
    • http://heldermusic.nl/ckfinder/userfiles/files/vimafoxidarunirimepijafad.pdfIn PDF document text
    • https://editionsitaliques.com/userfiles/file/xogomorakudoxeref.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f83a42de6---kuxep.pdfIn PDF document text
    • https://blagoustroystvo24.ru/ckfinder/userfiles/files/diwajinorevag.pdfIn PDF document text
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/jogowutapup.pdfIn PDF document text
    • https://eventpro-kontraktorpameran.com/uploaded/files/vogigejip.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16134942469e9b---99466267274.pdfIn PDF document text
    • https://ahirealty.in/admin/userfiles/files/xirenufejiziwikugokavonu.pdfIn PDF document text
    • http://malir-naterac.info/UserFiles/File/monavidu.pdfIn PDF document text
    • http://wanyuantemple.tw/userfiles/file/kejoberasimarumomip.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/96035017598.pdfIn PDF document text
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/makejim.pdfIn PDF document text
    • https://avphunter.ro/ckfinder/userfiles/files/wurajazidotojigijepej.pdfIn PDF document text
    • https://cicasoftavukatwebsitesi.demowebsiteleri.com/upload/files/6392662304.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/77945153525.pdfIn PDF document text
    • http://sanxuatbanthinghiem.org/app/webroot/uploads/files/10187497334.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+make+your+own+live+wallpaperPDF 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_off0000c6ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6EF 16984 bytes
SHA-256: f5f8974b6110046c2ecb2b325990a066af7ee11f0ee886414cb8b009b7d98202
font_01_sfnt_off0000f2d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D8 10696 bytes
SHA-256: e7edb814407b15bc0df8e0c0fd50be7ed9e1a1ead6dc805d560facd4024137cf
font_02_sfnt_off00010b58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1