Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b7d938e2bb4c52…

MALICIOUS

PDF

91.9 KB Created: 2021-04-27 00:56:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: ab08087f453456d322a35322efb9db7b SHA-1: 75c6eced2ab0d3ae1560a61bc9f92a68fb9c5afa SHA-256: a4b7d938e2bb4c5290f87e7062d349fd200cdbf14483b3b56f58312e1f46d3ff
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it's part of a link farm designed to host numerous links on disposable domains, likely for phishing or malware distribution. The embedded URL points to a suspicious domain, further supporting this assessment. No scripts were extracted from this sample, but the structure and heuristics strongly suggest a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://resalured.ru/strik?utm_term=wishful+drinking+lyrics+jonny+houlihan PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4403274/normal_60502cff8d4a3.pdfIn PDF document text
    • http://gijixig.22web.org/verbos_irregulares_espaol_lista_completa.pdfIn PDF document text
    • http://weridif.medianewsonline.com/bharathiyar_songs_book.pdfIn PDF document text
    • http://borejukeluteva.mygamesonline.org/adverb_clause.pdfIn PDF document text
    • http://rimiripa.mypressonline.com/vejozan.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490365/normal_6032935cb7cae.pdfIn PDF document text
    • http://sobuvide.mygamesonline.org/12411291369.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480149/normal_602be7c5b7974.pdfIn PDF document text
    • http://sokokusulamubi.22web.org/incident_response_policy_template.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://dexivovadoxexo.myartsonline.com/august_month_current_affairs_vision_ias.pdfIn PDF document text
    • http://netawuwimirixor.onlinewebshop.net/98217120263.pdfIn PDF document text
    • http://naxefugoxodikow.atwebpages.com/fosunupijurifesekow.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c45c900-9066-4895-aefc-c92395a8e9e1/88154861455.pdfIn PDF document text
    • https://3c59ccad-08dd-474b-8af0-a42d91f20399.filesusr.com/ugd/489ff0_a7007bc3064846829b6f8a544d3efb5d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ae856ecd-12f6-43c4-ad0c-6673e30d0339/11819349544.pdfIn PDF document text
    • https://8ed7b8cb-9bae-4def-ad9b-66b28cd11f91.filesusr.com/ugd/740d8c_ec57d179ce0b434693bb17e1d2701328.pdf?index=trueIn PDF document text
    • https://ff06b2c9-6223-4357-b4d5-1bf3807c749f.filesusr.com/ugd/717131_133bdc056f1a4e95a16836e03cc9be3e.pdf?index=trueIn PDF document text
    • http://bifakafuwal.rf.gd/foraging_books.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c89db6e5-ebf0-4a0d-a3c6-4a39a292c479/donopuzemenesamoxinoledo.pdfIn PDF document text
    • http://biwefejiza.myartsonline.com/fonimidemidimovow.pdfIn PDF document text
    • http://xirofapinowud.atwebpages.com/46462674533.pdfIn PDF document text
    • 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_off00011971.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11971 5220 bytes
SHA-256: 79b92d75c160ffba965fa877a11bc040aa471d7b863a4b0fc8ba66d0b541719d
font_01_sfnt_off00012b2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B2C 11972 bytes
SHA-256: ae203a5f597d25570034380cc16d458cfbd6236887d1b0d26d1acbf7bd95004e
font_02_sfnt_off000153ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153AE 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333