Malicious PDF — malware analysis report

Static analysis result for SHA-256 258f81bd5a8d2899…

MALICIOUS

PDF

103.0 KB Created: 2021-04-28 03:02:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: fbb33fe5afd82c69c94d528281446d5a SHA-1: 7d7b5ad11f3269dd1a44cc402f60f2a79d62d68e SHA-256: 258f81bd5a8d2899013a9d9beebcc31c3c15b413c66d03fd86ab4660e71efc19
186 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

This PDF file was identified as malicious by multiple heuristics and an ML classifier, specifically flagged as a phishing trojan. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The primary malicious URL identified is https://jumiwimov.ru/strik?utm_term=ucsd+health+campus+map.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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 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://jumiwimov.ru/strik?utm_term=ucsd+health+campus+map PDF link annotation
    • https://cdn.sqhk.co/zedawuzijis/eLnghgc/39953658178.pdfIn PDF document text
    • https://cdn.sqhk.co/zasemewiti/WsDiajd/iphone_12_120hz_confirmed.pdfIn PDF document text
    • https://cdn.sqhk.co/fijufupuga/gfgfMwy/gasaraxurikitod.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/b40407db-5fa5-4093-a7b7-279004747ca4/kofajutoza.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6a7fc123-65b4-4380-b3c2-ec2ca00adb16/46612094232.pdfIn PDF document text
    • http://bukaduxanob.epizy.com/rudufu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/95409cbd-ef5d-4054-9c32-b0a89aa09f11/how_do_u_count_atoms_in_a_chemical_formula.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2b740ec2-34b0-4b17-8b71-d3a7cb5e8316/java_j2ee_interview_questions_and_answers_for_8_years_experience.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/676f8bab-c270-47a1-8ddc-944a3792b4ba/felix_dennis_how_to_get_rich_audiobook.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c8a1b5a3-df02-4199-9981-2b2a0fb4c567/93288085160.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/93700279-cfbe-446f-87ec-af49dc870b38/the_fall_of_the_house_of_usher_movie_1979.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0127376-5dc5-426b-a3a0-1acc24cbec88/focusrite_control_tutorial.pdfIn PDF document text
    • https://7be326e9-a1fd-4761-a84c-83c904220737.filesusr.com/ugd/37e945_99a2bc4e1edf4ed8a457671beaf1cada.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/56622c4d-3eaa-4818-b60f-6b48692837f0/subway_steak_and_cheese_salad_nutrition_facts.pdfIn PDF document text
    • https://30621b86-6952-4b41-80af-4d24d830bc7c.filesusr.com/ugd/122077_9bb79fec3d0745c48307cb684635d1d9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1e11cd33-2c59-4cd3-a6cd-468964ae075d/nikavi.pdfIn PDF document text
    • https://34e2f0dc-0077-42bd-a047-efa2502e92af.filesusr.com/ugd/8a05ec_ee9163e1dd0b4fc1b7bddb579225d6be.pdf?index=trueIn PDF document text
    • https://a0bbd489-bf03-48a0-8e93-88abd0751e5b.filesusr.com/ugd/370ea2_2b87903d5b0d4305961cc5741373f5ca.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/025a942f-e283-4c73-b2ea-e9fbbeee79d3/92602475069.pdfIn PDF document text
    • http://datuzijopo.epizy.com/how_to_write_a_descriptive_essay_about_an_event.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2711fa60-ddc8-4ada-bf58-c2362cbba334/sleight_of_mouth_patterns.pdfIn PDF document text
    • http://sabasil.epizy.com/how_to_mute_microwave_lg.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_off0001569f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1569F 5208 bytes
SHA-256: 3ad0771bcab451032bd4070a85877b330da50a5c413e6c1ebc74fee6376fbd84
font_01_sfnt_off00016833.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16833 11340 bytes
SHA-256: 4924aad17e49b63e00d75340207281c388deb00f29d06e8535e784981abf2c02

Open this report in the interactive analyzer, or submit your own file for analysis.