Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab3de727c17bdf65…

MALICIOUS

PDF

80.4 KB Created: 2021-05-28 12:07:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 0dbbaf9fb6e3a55a62e0001b69679a91 SHA-1: ed3aa3b395136fa28a2480af717de8c0f0d12bdf SHA-256: ab3de727c17bdf658bbbc1ac24ce9dc5049b6a76d4d939415e66a0b2a8a14c76
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, and it contains a heuristic indicating a link farm of external PDF documents. The primary malicious URL, https://jacksth.ru/strik, is likely used to redirect users to a phishing or malware distribution site. Although no scripts were explicitly extracted, the PDF structure and the presence of external links suggest an attempt to exploit users through a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • 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://jacksth.ru/strik?utm_term=resumo+arcadismo+brasileiro PDF link annotation
    • https://xabolagusi.weebly.com/uploads/1/3/4/6/134631680/7554904.pdfIn PDF document text
    • https://matubupediguja.weebly.com/uploads/1/3/4/1/134131452/2672275.pdfIn PDF document text
    • https://zusiwugebibod.weebly.com/uploads/1/3/4/4/134484471/3981013.pdfIn PDF document text
    • https://tigasuzile.weebly.com/uploads/1/3/1/3/131379741/lopor.pdfIn PDF document text
    • https://dafelubuvotaxid.weebly.com/uploads/1/3/4/7/134753950/84a580805.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/c5d55145-cffe-4d77-bb15-5a9b90e361f2/82752715726.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/578ce640-223c-4089-a454-e74f13762710/36709992507.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9ad9375a-44e3-4094-bd75-fd0a7e609dff/journey_to_the_center_of_the_earth.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7aaf13e6-c3be-4650-aff4-b408a47ee0fc/zirisalijepojeba.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7baee2f6-fa62-4807-9f9f-60b0ab231dc6/wilixamaletaxegibazavusu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/400311d7-5c6e-4e1e-b6b3-62f240b0ae33/jebajuk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/af995337-91bf-416d-978f-7f3b6a1092fb/60409635014.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8da8a0c9-0fe5-41c0-b1f2-63e0c7f8e500/54784143215.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/728145a2-139a-4e0b-a370-d84580f44036/61098789590.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/621ae726-ce36-41b7-aae1-2a51391389c8/what_are_pointer_operators.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/842da197-8a15-4720-90f9-44b7b3ba2521/zukamatasabuzuk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ed514db4-1892-41c1-8613-2b2e5438c943/eiu_worldwide_cost_of_living_2019_full_list.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/33228a0f-278a-4970-8f49-bf99b201bdcc/dojidugutozupizituvilas.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/148ac054-14d1-40b6-a809-97e1804fa03f/modelo_de_acta_constitutiva_de_asociacion_civil_sin_fines_de_lucro_per.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/39b7fdea-e763-4cf5-8a12-f891d3775179/vedic_maths_tricks_free_download_in_telugu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6ad87c34-9ee5-42b5-94dd-836c8fc0ca20/anthony_de_mello_awareness_review.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_off0000faaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAAF 5232 bytes
SHA-256: c133b17dd8bf7497c83a320adee1505d464690e2d4888b04062fdc1e28008eb1
font_01_sfnt_off00010c5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C5E 12704 bytes
SHA-256: 1fac0cc70d488ede6a6200d657c7286b9ba1b2dd1a40f3dcba67473acbdac896