Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f8d4330bddb7f40…

MALICIOUS

PDF

83.5 KB Created: 2021-03-24 02:50:02 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: bc04c8ae20dca5bb7861b261de07de28 SHA-1: 3ce11c4b36f276fb8c5d7595fc7b1746894bc419 SHA-256: 9f8d4330bddb7f402adcbdf4d90f8466f0d54d37e59c51a30ba3ec5d56a0b642
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file flagged as malicious by ClamAV and an ML classifier. It contains a large number of embedded links, many pointing to redirectors and disposable hosting, suggesting a link farm or phishing attempt. The presence of a link to 'crophysi.ru' with a 'santa claus number' keyword indicates a potential lure, possibly for social engineering.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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 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.
  • 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/wix?keyword=santa+claus+number+for+bad+kid In PDF document text
    • https://cdn.sqhk.co/gejupajo/ZpPhbjh/princess_crossy_game_road_funding.pdfIn PDF document text
    • https://cdn.sqhk.co/metexemoraga/x2jfehb/bahubali_songs_naa_songs_2018.pdfIn PDF document text
    • http://skidki-day.site/fabalekovi0m8.pdfIn PDF document text
    • http://digitalcalakk1.xyz/nakedutivezdo1zd.pdfIn PDF document text
    • https://cdn.sqhk.co/rozesivotix/dljgiig/average_gas_prices_in_california_2018.pdfIn PDF document text
    • http://reduslim-shop.site/archipelago_tour_with_guide_stockholm3btfz.pdfIn PDF document text
    • http://servempieza.site/laxokobu8ajpm.pdfIn PDF document text
    • http://allieshouseofhope.com/28661253928yg90v.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://aa0e52d0-3c12-4d86-bfd3-e3284f950a51.filesusr.com/ugd/eb1974_c99985bc182f4f3f957880b8ccb828af.pdf?index=trueIn PDF document text
    • https://089130c0-62ae-4bf1-a93c-656440fe8451.filesusr.com/ugd/738632_47ffe6a8b4d643faa90d4c401a6fabc0.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/716c8401-9da6-4315-b78d-cfbef1f55e9e/vavosojazinotexi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a4a0173f-1448-4576-b232-87491432751e/16035343173.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d11d0ef0-f2fc-4e4c-a907-f4bc316c66cc/yamaha_mg124cx_for_sale.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/801fbc21-d970-45bf-bd8f-48ccc792fa68/gadowerakemubebotaregixuw.pdfIn PDF document text
    • https://5663e088-3595-439c-971a-5873693bee35.filesusr.com/ugd/e98895_504812b72b3e4a9fb4bf943a600d2f75.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/343948ac-23db-4c57-8f30-68a54bbb6527/19194032858.pdfIn PDF document text
    • https://ff4d9611-e7ea-45f2-85d3-f0b464ef817f.filesusr.com/ugd/48f461_db57cee215134e5fbbdfe5379923aa47.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1ce10e36-0298-46f0-a060-dcbf9b3a82fa/3047051376.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9c936b3f-f112-41e0-b1f8-c99799febfad/craftsman_yt_3000_snow_blower.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3a1d7cfd-8faf-41a0-b9dc-4d3f8fca89f8/gluten_free_fast_food_options_australia.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_off00010a03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A03 5476 bytes
SHA-256: d9570dedda6c6928247a06f8fc8f6315d55cfcf9f8372c262c09892ac4099e22
font_01_sfnt_off00011c84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C84 10592 bytes
SHA-256: d66a31f7fd9c474d8cb6d7061ede9e16866dd8ad2a8cc3bc54d6cef7e60696aa