Malicious PDF — malware analysis report

Static analysis result for SHA-256 af4c9a9580960430…

MALICIOUS

PDF

70.8 KB Created: 2021-04-03 21:05:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 839115346a0f6517f1f4c9585c5abb38 SHA-1: cef630991e0fbcdeeea153204945111d72f2d9f4 SHA-256: af4c9a95809604306ee7f20080bb295968f0f9f8f47a6e41e924dd4ccab0051a
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for distributing further payloads or redirecting users to malicious sites. While no scripts were explicitly extracted, the PDF structure and numerous external links are indicative of a malicious document designed to exploit users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://xezojetit.ru/strik?utm_term=refurbished+herman+miller+aeron+chair+size+c PDF link annotation
    • https://cdn.sqhk.co/kibedutej/dejjl6E/idle_heroes_star_system.pdfIn PDF document text
    • https://cdn.sqhk.co/xubodijixali/Nha0mge/96877417599.pdfIn PDF document text
    • https://cdn.sqhk.co/bikezuku/lZhg1id/xujizizuruzezeruwewemigo.pdfIn PDF document text
    • https://cdn.sqhk.co/bitizulokiva/iidtkhg/futukafavud.pdfIn PDF document text
    • https://cdn.sqhk.co/wodaximewule/jaiblrm/patesize.pdfIn PDF document text
    • https://cdn.sqhk.co/jawutuwek/jjYidgi/42191719352.pdfIn PDF document text
    • https://cdn.sqhk.co/tuzijaxab/TgghfB6/18422526505.pdfIn PDF document text
    • https://cdn.sqhk.co/xuzalolotagi/cKhipHD/battle_dogs_game_free.pdfIn PDF document text
    • https://cdn.sqhk.co/dagozuwemep/cWpVF3a/kiribimaliso.pdfIn PDF document text
    • https://cdn.sqhk.co/kepilujofeje/ha0sjbu/biwujerobavuforujobe.pdfIn PDF document text
    • https://cdn.sqhk.co/givesaxi/Ejfhfhb/how_to_do_water_marbling_nails.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://visobiwedixupip.rf.gd/xebavuz.pdfIn PDF document text
    • https://2559d30b-64cd-4b4d-aaad-e76a675dde99.filesusr.com/ugd/f5a024_6d135a97e1f943b69e9207e550460dbe.pdf?index=trueIn PDF document text
    • http://pepukogabam.rf.gd/cloze_passage_for_grade_1_with_answers.pdfIn PDF document text
    • http://terunakef.rf.gd/47221881243.pdfIn PDF document text
    • http://dejelevimira.epizy.com/vukuwapukedubegepin.pdfIn PDF document text
    • http://demuwesax.epizy.com/java_spring_mvc_application_example.pdfIn PDF document text
    • http://rufuregebedus.rf.gd/rejexepez.pdfIn PDF document text
    • http://fepufikegag.rf.gd/bobefu.pdfIn PDF document text
    • https://6acf0ca1-aa41-4771-8b91-54baff69ee7f.filesusr.com/ugd/7d1dc9_5c67077d9574476faa37b17ffeea9584.pdf?index=trueIn PDF document text
    • http://besipobewawite.rf.gd/tuxefata.pdfIn PDF document text
    • https://50bf384a-eeac-4f26-a262-e2ba1a5e00ba.filesusr.com/ugd/17159d_a70c19f1225c48e59ee224d2e9b30393.pdf?index=trueIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d5b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5B4 5456 bytes
SHA-256: 6c7a82cc448d22c65ceaedc23f35adcde4cd68c0f4134b1d24959900a5d2586e
font_01_sfnt_off0000e822.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE822 10888 bytes
SHA-256: 2d6b5527daf02a612cf509cf7b7b907530124be760f50ce916ddfe4efa51a0a7