Malicious PDF — malware analysis report

Static analysis result for SHA-256 a58ac5203eb7993f…

MALICIOUS

PDF

117.4 KB Created: 2021-04-13 15:14:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 90a58349df082ebaf39aba40ff510a0c SHA-1: b4612ca2bec43d405ee43816a99ddb4d9742a2ab SHA-256: a58ac5203eb7993fbf58e87062c14a6c6edf8f4727e88ce736ceeb75bd255037
184 Risk Score

Malware Insights

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

The PDF contains embedded links to known malicious redirector infrastructure, specifically disguised as a firmware update. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, contains references to 'firmware update' and 'wkhtmltopdf', suggesting a lure to a malicious URL for potential malware delivery or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://crophysi.ru/strik?utm_term=avh-x3600bhs+firmware+update In PDF document text
    • http://duzegotola.medianewsonline.com/98206496642.pdfIn PDF document text
    • http://wejuveziwep.mypressonline.com/carburetor_working_principle.pdfIn PDF document text
    • http://pitikudefojeken.getenjoyment.net/les_accords_piano_jazz.pdfIn PDF document text
    • http://midarujiwuvi.mygamesonline.org/qualities_of_effective_intercessor.pdfIn PDF document text
    • https://cdn.sqhk.co/repejuvovod/a7c6ENS/45473300877.pdfIn PDF document text
    • http://tb-films.ru/jazisomadumubegikv5834.pdfIn PDF document text
    • https://cdn.sqhk.co/pewovixosafu/Mgc8Ihb/ninja_knife_sharpener_as_seen_on_tv.pdfIn PDF document text
    • http://gagimubu.mywebcommunity.org/jane_austen_pride_and_prejudice_audiobook_free_download.pdfIn PDF document text
    • https://cdn.sqhk.co/dinigivo/fxhr4hd/skyrim_dragonbone_arrow_id.pdfIn PDF document text
    • http://mklhhhh.space/solucionario_mecanica_vectorial_para_ingenieros_dinamica_11_edicion_gratisrpfui.pdfIn PDF document text
    • http://lobulezinovux.medianewsonline.com/65039534261.pdfIn PDF document text
    • https://cdn.sqhk.co/gowamojon/6gdjbhg/29653759958.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/1da9d667-501b-4537-9ade-9e7830a14ef1/53222169867.pdfIn PDF document text
    • http://dijipola.onlinewebshop.net/conservation_of_biodiversity.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/62db533a-385e-4c56-b231-3380bf73eb81/73983613201.pdfIn PDF document text
    • http://widepidaba.atwebpages.com/digital_electronics_textbook_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/333cbb31-20be-45e7-8b31-a65aaca07d38/lolixenexipi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5ebd745e-85f5-4724-89db-668af17530f3/54560940300.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6afef892-f168-45fe-9759-9b401ebd83c4/how_to_prepare_for_social_work_placement_interview.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_off00018a4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18A4C 6092 bytes
SHA-256: ef29e14726ae73439407f9b6db9df3c169586c510df20e01ede58ebcff8057d2
font_01_sfnt_off00019ef5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19EF5 11504 bytes
SHA-256: e0acd88b3d8d2305ecfe55c40a36b00f84ad8f0736d10ffc144b74370d1cddb7