Malicious PDF — malware analysis report

Static analysis result for SHA-256 76d216539d85be77…

MALICIOUS

PDF

82.0 KB Created: 2021-09-13 15:57:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 791a3bd42b63dff73ba62abd2a362956 SHA-1: 1ddf82ec23323c84c913225f9d6ff1d10ea1cc68 SHA-256: 76d216539d85be77f5f7c2d4339ced53c9fe0bc4e76cc38a3815a195d581980c
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and URL patterns suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://robwalker.net/fckupload/file/luwitezomopugifojatudu.pdf In PDF document text
    • https://fluffy-chins.com/images/file/gavajuparor.pdfIn PDF document text
    • https://ww150003.linebot.net/upfile/files/20210910035802.pdfIn PDF document text
    • http://cecev.com/stockages/files/wimowawap.pdfIn PDF document text
    • https://nirkongrp.com/ckfinder/userfiles/files/44159216589.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/kizumevusuzam.pdfIn PDF document text
    • http://kowel.com/ckfinder/userfiles/files/1631004935.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613b99b7bcecc---24175602801.pdfIn PDF document text
    • https://huaku3c.tw/uploads/files/202109011322576478.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210913024648.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613b5af5ce01b---joverogukasufabare.pdfIn PDF document text
    • https://sanaspinler.com/calisma2/files/uploads/xuneta.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0e87150e0---921905102.pdfIn PDF document text
    • http://emekyesiltepe.net/images_upload/files/juwalosafa.pdfIn PDF document text
    • http://serenetour.com/image/upload/File/34508885064.pdfIn PDF document text
    • http://dytac.hk/userfiles/61461999043.pdfIn PDF document text
    • http://softwaretesting.kr/club/data/userfiles/file/20210912042051.pdfIn PDF document text
    • https://autotoner123.com/home/autotone/public_html/ckeditortest_WORKING/ckfinder/userfiles/files/dibikifidotose.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613b5b0d6cd67---jururodi.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/gsn6it1sr872bl2e0ajdq1df16/kakigulezu.pdfIn PDF document text
    • https://arendic.cl/files/40621292018.pdfIn PDF document text
    • https://e-midas.ro/files/file/85808244125.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=format+sd+card+as+internal+storage+not+availablePDF 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_off0000daac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAAC 18016 bytes
SHA-256: 4866d56d6efc998cc7e03f7965704c0d8250c70144a3d64aadeeea27292475de
font_01_sfnt_off00010955.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10955 10896 bytes
SHA-256: cd71a6ae337201158226542006d157f65b10157ba115bedf64c23d9c5d577562
font_02_sfnt_off00012256.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12256 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1