Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5395b7da84ead3a…

MALICIOUS

PDF

84.5 KB Created: 2021-06-12 08:14:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 1b11e0eee0d5b2535c3a49ed82b5f3fd SHA-1: 51c09d0ceac79acaa4ef5b8345d920b14c8fb492 SHA-256: b5395b7da84ead3af3485c5d4c6671c06dd792633389618bfdbbb7382de8e326
186 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by a machine learning classifier and ClamAV. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The primary URL, vilenefex.ru, is likely used to redirect users to malicious content or further phishing pages. No scripts were extracted, but the PDF structure and link farm indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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://vilenefex.ru/123?utm_term=bpt+syllabus+ccs+university+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4371258/normal_60507bfca7ae4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465142/normal_606e11ca9dbcf.pdfIn PDF document text
    • https://tejojobowadame.weebly.com/uploads/1/3/0/8/130874570/xuditudil.pdfIn PDF document text
    • https://sudiduku.weebly.com/uploads/1/3/1/4/131452825/8a1950ccd79d61a.pdfIn PDF document text
    • https://jalupibu.weebly.com/uploads/1/3/4/5/134520797/sivoze.pdfIn PDF document text
    • https://tepikibinaf.weebly.com/uploads/1/3/2/3/132303010/46aaa2.pdfIn PDF document text
    • https://zoxutelipiroga.weebly.com/uploads/1/3/1/8/131871488/7be068cffa0.pdfIn PDF document text
    • https://zitokafinug.weebly.com/uploads/1/3/4/7/134738680/4d83197b6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370059/normal_604e13719adb0.pdfIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://nebapelamive.pbworks.com/f/gesufez.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9fc075b8-60ad-4016-b728-f2e63a45081a/mupokixawuluman.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e97e53ae-df53-4937-bd92-6d184ebd5e84/happy_ending_movie_song_ringtone_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/629aeea5-72d3-4b40-9ed9-ce52b5d0d8bb/46421137362.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/25f7e341-d1ed-4e03-86b9-b8a3459e8748/lumorevadotevimoke.pdfIn PDF document text
    • http://kevesefazoga.pbworks.com/f/57387956353.pdfIn PDF document text
    • http://fijinatuzut.pbworks.com/f/grade_2_comprehension_passages_with_questions.pdfIn PDF document text
    • http://lufokomarib.pbworks.com/w/file/fetch/144469125/bohemian_rhapsody_tab_piano_to_guitar.pdfIn PDF document text
    • http://degomulaxib.pbworks.com/w/file/fetch/144878814/81182937687.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/244710a7-5832-496b-9e3a-a3dcb066d1d2/what_is_the_best_buzzer_beaters.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
stream_004_off000131e4.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x131E4 5312 bytes
SHA-256: f95d56ac3f511e9d8e722d40fa869821123f711a2a4d4b4fb1a3f8a0f35a77cc
font_00_sfnt_off0000f998.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF998 5500 bytes
SHA-256: 62f6e327e15f307f0c8c11b542658775ad434fe9fe7bf5768f5e31bf022f567a
font_01_sfnt_off00010c68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C68 10940 bytes
SHA-256: a23ae849151dd1a601fad81395f9f66897f4cd55576857b205329f7f0b6e6aea