Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f73856d0e3f1ba6…

MALICIOUS

PDF

84.5 KB Created: 2021-09-02 20:26:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 20fe565401df80c9d1724d98e793930b SHA-1: 7cfada044a0fb9af69d2df295853b8e95b7223ed SHA-256: 3f73856d0e3f1ba6b2dd11c43c5e8a277f89f42a562cd39c4bed16c7def88527
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by an ML classifier. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users. Additionally, it features a link farm with multiple external URIs, some pointing to potentially compromised CMS upload directories, indicating a possible attempt to host or distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://jagominum.com/contents//files/xobasesefelazi.pdf In PDF document text
    • https://www.soroptimist.be/oldsite/intranet/ckeditor/ckfinder/userfiles/images//files/42036941778.pdfIn PDF document text
    • http://hebertfamilyreunion.com/clients/3/32/3272330ca4c68e8b1120eb7f178c7a05/File/2345239905.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a8da2614a31---vexanaropowiluzofawax.pdfIn PDF document text
    • http://seyrimerdin.com/userfiles/file/komekakawesaxexalejorali.pdfIn PDF document text
    • https://louvre.lv/res/wysiwyg/file/tuduxusixibukepiwo.pdfIn PDF document text
    • http://kientrucnhacuagio.com/upload/files/bivodowajurowitebalo.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d5a81548b---mefulususo.pdfIn PDF document text
    • http://aep-tc.com/cache/fck_files/file/likujufuzewut.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/3e04d4112b4d68de5a1042e16b77bee4/rajelevenovamemer.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/kusogegovotewefibubinawef.pdfIn PDF document text
    • https://habibitours.org/ckfinder/userfiles/files/romonoso.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/jirutu.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/8bf3cc30e307b570e8dfbd9b5a1530ad/34211660369.pdfIn PDF document text
    • http://studionegro.net/userfiles/files/2970539460.pdfIn PDF document text
    • http://brickchamber.com/ckfinder/userfiles/files/bitiredesaseboremezo.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609812e6e185f---tigemig.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/apqh6jltg47m7lhebgvutlo35i/vedolidivasogukegolad.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a63fef07402---25675717230.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16097b74c75134---jifasegufubinemenegisit.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/99232533811.pdfIn PDF document text
    • http://regalmotors-jp.com/js/upload/files/8683433208.pdfIn PDF document text
    • http://pelesiuvalymas.lt/i/File/89827212109.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/063c0e50d20aba83630e1000b3d397c1/95521951586.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=correcteur+d%27orthographe+pdfPDF 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_off0000e343.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE343 19384 bytes
SHA-256: a03b228ad082f9db9aa23924f17c5697ef81a28af7f5df99ca1836dd2a033f38
font_01_sfnt_off00011439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11439 10656 bytes
SHA-256: 6004acd9989eb02058b02d0874982ac3f3f0590b82b6249c890c61c7cdad8d6c
font_02_sfnt_off00012ca6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CA6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1