Malicious PDF — malware analysis report

Static analysis result for SHA-256 905455d9faff412d…

MALICIOUS

PDF

93.9 KB Created: 2021-09-18 18:38:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9cd60a41336cb169c06a925d3d2a5182 SHA-1: 8e6de3fe933448720a9bf8bc6d533e6982c99f33 SHA-256: 905455d9faff412de90a085392f64b60aad91162e8214390ac5e71d0c422e9b1
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous PDFs hosted on compromised CMS uploads, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The document body is unreadable, but the presence of many external links and the high risk score support the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://opusincertum.it/userfiles/files/minorevajadiponezodonef.pdf In PDF document text
    • https://yp05.com/_UploadFile/Images/file/xopuwojulomal.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/medokulafo.pdfIn PDF document text
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/minokadexufubuxedifugakef.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/75842620530.pdfIn PDF document text
    • https://grupo-bahia-real-estate.com/ckfinder/userfiles/files/kisabeguzozogixozevifixij.pdfIn PDF document text
    • http://balalajka.nu/media/69412968245.pdfIn PDF document text
    • http://boldogelet.hu/media/64752120016.pdfIn PDF document text
    • http://seamcc.com/UserFiles/files/xasutadexemogigozawefo.pdfIn PDF document text
    • https://fceresources.com/ckfinder/userfiles/files/wojowat.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///rokokutawemon.pdfIn PDF document text
    • http://olgapolyakova.com/files/files/85298078315.pdfIn PDF document text
    • https://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/tedanofedipalek.pdfIn PDF document text
    • http://svatba-emi.com/uploads/pages/files/tixovisorafexiwavutofi.pdfIn PDF document text
    • http://pensjonatagat.pl/userfiles/file/11510758832.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/161434c9b30e00---marededalakel.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/161458823b9513---jajujoxewikimuwanadipemoz.pdfIn PDF document text
    • http://take114.kr/FileData/ckfinder/files/20210910_F1DFAF9203F0A8CD.pdfIn PDF document text
    • https://lesrimaudieres.com/images/uploads/file/83303253488.pdfIn PDF document text
    • http://www.iciparis.ru/ckfinder/userfiles/files/97792600532.pdfIn PDF document text
    • http://sweatrinserepeat.com/ckfinder/userfiles/files/88168911798.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/lugewifizep.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/7968htc4ph2r9seev36k7plsn5/46931277671.pdfIn PDF document text
    • http://thepokewave.com/uploads/files/juvuzozir.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=text+compare+in+notepad%2B%2BPDF 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_off000105bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105BC 19644 bytes
SHA-256: c09eec3dd312eefc10ccc8750ba64568374a9a44b3098788eb07dfb00865dead
font_01_sfnt_off000139be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139BE 10524 bytes
SHA-256: 0b4ecd3833ddd217fa2898936acf8ab573bbac3143abb49b748a0b578b4cc35a
font_02_sfnt_off000151b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x151B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1