Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac9d1e72aa0a9df5…

MALICIOUS

PDF

79.5 KB Created: 2021-04-13 05:19:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 25b940f6f75a81ffbc65801fd6502d5a SHA-1: 6ea10ce9786c8f54ddb21f403b1c08c8bd52b999 SHA-256: ac9d1e72aa0a9df5db8c90876021b9e99d5552e0d6827bd7070f843c8f0b45ac
186 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous external URIs, with a primary suspicious URL being https://golowaki.ru/strik?utm_term=it+service+operation+meaning. The heuristic PDF_SEO_LINK_FARM indicates a mass of external links, suggesting a potential phishing or SEO manipulation scheme. No scripts were extracted, but the structure and URL patterns point towards a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://golowaki.ru/strik?utm_term=it+service+operation+meaning PDF link annotation
    • https://dawanuma.weebly.com/uploads/1/3/4/3/134305997/cdd5ac9a0d.pdfIn PDF document text
    • http://norasidifonilov.22web.org/38635723271.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366978/normal_5fdad751a8328.pdfIn PDF document text
    • http://letilemugemin.66ghz.com/examenes_pet_cambridge_resueltos.pdfIn PDF document text
    • https://resawipodejevi.weebly.com/uploads/1/3/0/8/130814711/6523178.pdfIn PDF document text
    • https://vinenuji.weebly.com/uploads/1/3/1/4/131453259/dukowatupozonavalota.pdfIn PDF document text
    • https://bewimowijukoja.weebly.com/uploads/1/3/4/5/134584545/840bbc44.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4452395/normal_601c5cba852b5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369775/normal_5ff910c9f1ad4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502920/normal_601e051f772f2.pdfIn PDF document text
    • https://dajidavibaral.weebly.com/uploads/1/3/4/6/134606929/tiliwibevitemaki.pdfIn PDF document text
    • https://xodozevonewoze.weebly.com/uploads/1/3/1/3/131384462/fipoputimaw-goxafozebir-vawejuxapogu-xofapuluzuv.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/c2eb0bee-5456-4226-ba3f-d3fec138baca/88849296256.pdfIn PDF document text
    • http://jufofokisib.epizy.com/81589643596.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6dd5879f-5159-4fec-9f6e-183530dc3b94/ge_advantium_microwave_oven_parts.pdfIn PDF document text
    • http://kujugabudejise.rf.gd/80448059430.pdfIn PDF document text
    • http://serobamemesazan.rf.gd/naboz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bca2de6c-b780-4bd3-9afe-e1a4500bdaca/amana_front_load_washer_instruction_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e00fbc83-f7dd-42d3-84c1-6ecfff54caff/84063238588.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/db480ff4-68ed-48bb-ac0a-cc8d64c0b59d/bepepezarusoxalowav.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5751fb87-97cb-436f-aaf5-55d810889ef4/golf_buddy_watch_wt3.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98735f0d-f263-498a-b18c-fc71a86cb3a6/venepowexojurolopunemam.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4dedb8a7-f93c-4fb1-9f74-7e519f86131a/easy_guitar_chords_songs_2019.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f9b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B9 5220 bytes
SHA-256: de32ea392926b200af02e4c651842afa476d346940c9c544b698476d3ff230d2
font_01_sfnt_off00010b6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B6E 10912 bytes
SHA-256: 0e3f7a8443fe0fc988c48e2d3d9f252fc050f8c33f126aad2a5fa50852c16db1