Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cf2b56aae44c41b…

MALICIOUS

PDF

75.5 KB Created: 2021-06-09 05:27:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 37868b647224377d138127a84f38d566 SHA-1: 3e33cb4c7c6db9275a8aa4aab58197d028c47cc6 SHA-256: 1cf2b56aae44c41b03778ad095b9ac554d91dc2b2a11cc1b0aacd4b02d153730
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, with a specific ClamAV detection of 'Pdf.Phishing.Trojan'. The presence of an external URI pointing to 'infrive.ru' and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggest a phishing or link-farming attempt. Although no scripts were explicitly extracted, the nature of the heuristics and the malicious verdict strongly indicate an attempt to redirect the user to a malicious site, likely for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://infrive.ru/pbw?utm_term=cat+breeds+list+with+pictures PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4425910/normal_5ffe1b12c89e3.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4485172/normal_60b6ba6accf75.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408180/normal_5fd9894397447.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391649/normal_5fe8fbd193535.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/0d4de342-0627-4dae-874a-94a6a398c781/badger_100-1_garbage_disposal_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7e7b058b-27cf-4e07-95d7-482ea068cf33/85277878564.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a3061d64-3746-43b6-8e67-4e6727c95c24/84597251931.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0af9e745-22eb-4b67-bab5-f498ff43398a/poulan_chainsaw_3400_owners_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4c7534b9-de86-4f84-8b93-884a93346932/samsung_ln32b360c5d_remove_base.pdfIn PDF document text
    • http://sowenux.pbworks.com/w/file/fetch/144770970/juzukexurotubesugivevox.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/24699126-30b2-4f8b-9147-44f0c084d162/zorogasagi.pdfIn PDF document text
    • http://mibegenav.pbworks.com/f/dabajukavijodawumitami.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ca1cb2cb-f48f-4824-92c9-5072d8388a35/love_is_fake_lyrics.pdfIn PDF document text
    • http://nagomax.pbworks.com/w/file/fetch/144570483/vinowuxigefatetesenumiru.pdfIn PDF document text
    • http://kibumezi.pbworks.com/f/diogenes_de_sinope_obras.pdfIn PDF document text
    • http://nagomax.pbworks.com/f/crt_tv_troubleshooting_guide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fa12c539-5c68-4d1a-b0ce-2834858a910e/sajamaj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dfe5e3e8-7936-469a-9a68-ccd957bf949d/where_can_i_donate_soft_toys_uk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6e96999e-9097-495d-8b66-4de7ccf5b241/how_to_load_swingline_high_capacity_heavy_duty_stapler.pdfIn PDF document text
    • http://mibegenav.pbworks.com/f/seluvabalodadedamibo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cb884b99-3bd8-4208-9089-787bfd8dc709/xaxijukivekokukomagumo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5b8f893e-3488-4b37-bd2a-c5515e89c062/manuales_cto_2018_gratis.pdfIn PDF document text
    • http://gozuwef.pbworks.com/f/what_are_the_difference_between_meiosis_and_mitosis.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_off0000ec9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC9F 5296 bytes
SHA-256: 6f33cf38d3c076ccb5f2edd4a6fac78f636fec4fe18fecd8b5dc9aea282d8fc0
font_01_sfnt_off0000fe9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE9E 9984 bytes
SHA-256: a1bb228e761f9cddaa5bb61ccee37f81052a8140658b1fe278b12f9dbc2ee4d1