Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef8019c51e7b040b…

MALICIOUS

PDF

81.4 KB Created: 2021-09-12 22:47:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0d5a548b742135c0ac1a417c6e75ce79 SHA-1: 5a2c7c8987c01cdae6a85251fcc5425f84e8efd3 SHA-256: ef8019c51e7b040b7f7e6486e2fe17dc1c892d09f5f96b033ed7ea4c3192e05f
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 the document functions as a link farm, directing users to multiple websites, some hosted on compromised CMS uploads and disposable domains. The primary goal appears to be redirecting users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16132dd89cefa9---felutipusemuguzajavobewe.pdf In PDF document text
    • http://narnivet.com/userfiles/files/25318516937.pdfIn PDF document text
    • http://apismorava.eu/docs/leradoje.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/18243997491.pdfIn PDF document text
    • http://harchovyk.com/userfiles/file/titojenanupabasewivudevu.pdfIn PDF document text
    • http://gintaras.cz/userfiles/file/96402935746.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/gojateniliz.pdfIn PDF document text
    • https://organicearthfiji.com/documents/file/1902975745.pdfIn PDF document text
    • https://villanakarin.com/userfiles/files/62190352858.pdfIn PDF document text
    • http://chip-chup.hu/upload/file/fabubadaranepewewukejana.pdfIn PDF document text
    • https://trungtamgiasuhcmmq.com/uplaod/quangtri/files/kotumanimuw.pdfIn PDF document text
    • https://candbco.com/ckfinder/userfiles/files/dinibemukijoxirilipu.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613856468d83e---62689007228.pdfIn PDF document text
    • https://tigaintan.com/contents/files/76694815455.pdfIn PDF document text
    • https://elpollopaulino.com/cenavarra_userfiles/files/90175713250.pdfIn PDF document text
    • http://viorina-deko.com/images/file/81950679078.pdfIn PDF document text
    • https://noriupapildu.lt/ckfinder/userfiles/files/77466600464.pdfIn PDF document text
    • http://pune-india.info/userfiles/file/fepekekizakijigix.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134c9874e4d6---rimoleto.pdfIn PDF document text
    • https://cuichi177.com/uploads/files/202109091906126645.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/k7nh2q2222rt115uofmpj3lqd6/37840596719.pdfIn PDF document text
    • http://stmrcstvm.com/userfiles/file/58567754639.pdfIn PDF document text
    • http://iglozawiercie.pl/zdjecia/file/dorapelifixukezavip.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=create+gif+app+androidPDF 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_off0000dadb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDADB 10492 bytes
SHA-256: 94a6af44a12d9a8a4082038297052b71632d02a1899aa2d15a4f940b75a0e530
font_01_sfnt_off0000f299.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF299 17408 bytes
SHA-256: 1a8ed3f126d5a41f78059abd1e62decccd9ccf8556823348850692ff7b690c08
font_02_sfnt_off00011fb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FB9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1