Malicious PDF — malware analysis report

Static analysis result for SHA-256 41f9acf691b76c4d…

MALICIOUS

PDF

158.1 KB Created: 2021-06-18 21:36:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: b9a03e4b7d66072f50f114293acc1d36 SHA-1: 2b57eabe48766f5eb4195d410e738a876bbfcaef SHA-256: 41f9acf691b76c4d50409fd3ac919b15a81bf87116aaa67d205a173c7e90f68d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/etpd70jt39k0aq16nced28d706/59655443547.pdf In PDF document text
    • http://snsi.jp/image/news_file/sejuzufakefavikipamidel.pdfIn PDF document text
    • http://aivieksteslaivas.lv/userfiles/file/mimipibi.pdfIn PDF document text
    • https://jamurgoreng.net/contents//files/37594958608.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/sunetexugiselerinewaper.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609110ce62bca---70513534488.pdfIn PDF document text
    • http://auksozvynas.lt/userfiles/file/70803569647.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/lenuxo.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/95709352662.pdfIn PDF document text
    • https://pinpointfeedtech.com/ckfinder/userfiles/files/92832123445.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608b37fb9c535---molokidezinerovira.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/9a098422c1cbb6efc62ae0ebfacf1676/gelebolenatipufulume.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16075d13ecf2cd---tokumejixusukokoxoremibu.pdfIn PDF document text
    • http://lempreintedubois.fr/userfiles/lempreintedubois.fr/file/melokagimolobefa.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/8cd71bd61380c900ef2224ca4d31e774/fusixapixapuxivek.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/r60kl6tqoeqo5ntgukm38ob21s/86071888895.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/6c82dba3dc6510aa1c41722c11c0f7b6/vepejimudovikinuxoro.pdfIn PDF document text
    • http://fontawesome.iohttp://fontawesome.io/license/In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=grade+10+math+module+1st+quarter+pdf+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00020bbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x20BBF 12240 bytes
SHA-256: 55519a2b6d6e01de19fae1845f623ec59f0e4c46b91c22d976b4ad43abd107e6
font_01_sfnt_off00022cfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x22CFD 5888 bytes
SHA-256: 862942572c6b6627588192da99c3965f410b6183c4c180c0ff44cb9af2b43c64
font_02_sfnt_off000240fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x240FA 12236 bytes
SHA-256: 4ed17c896fc6ff5fb610707b4148389604bbd61fd34d81ff5347bb2a7d99228d