Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcdcb5cd2ebb11ab…

MALICIOUS

PDF

103.6 KB Created: 2021-06-11 10:48:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 4057c8124c8c0185bdef52d188a882d1 SHA-1: d25943a970d8502b1507ff6924a3485bb4f89c34 SHA-256: dcdcb5cd2ebb11abe9669b832c9dc4f6da9c7b3e42adf0a63ecbc06134d12ea8
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The embedded URL and the PDF's structure point towards a spearphishing attachment as the initial access vector.

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://pistant.ru/pbw?utm_term=a1+reading+passages+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4427093/normal_601a3304b19f8.pdfIn PDF document text
    • https://veregatuvodomos.weebly.com/uploads/1/3/3/9/133997599/6736a901bd2cf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380540/normal_6015f0dd56a22.pdfIn PDF document text
    • https://zomoxiwoginu.weebly.com/uploads/1/3/1/6/131637743/fb6f69.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369161/normal_606355370bdef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383451/normal_60b90dd1d0f04.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496582/normal_60331d82c8294.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447089/normal_6030a8c2dc49b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://rizukokodi.pbworks.com/f/25274100263.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b135ae3f-6949-4635-ba0b-b4159841e083/covid_testing_near_cypress.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/64893d3f-9c9f-4025-90e5-987782cf1ac0/filmy_wap_punjabi_movie_2019.pdfIn PDF document text
    • http://zuwofig.pbworks.com/w/file/fetch/144536898/scotts_turf_builder_edgeguard_mini_broadcast_spreader_settings.pdfIn PDF document text
    • http://piwazufoli.pbworks.com/w/file/fetch/144772509/daily_mail_kakuro_answers.pdfIn PDF document text
    • http://namebitepu.pbworks.com/f/holt_mcdougal_literature_grade_8_answer_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/35435dd1-360c-4ae0-bb4e-64722d8c0ef7/do_ipods_have_bluetooth_capability.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/18503588-2898-4e8b-a33f-2cc84887f135/how_much_is_a_reach_forklift_licence.pdfIn PDF document text
    • http://guleribiko.pbworks.com/f/what_are_attention_getters_for_speeches.pdfIn PDF document text
    • http://bezawagiga.pbworks.com/f/48729889484.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/93990a9f-c267-4282-ad33-87ce83e90b5c/35744413448.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_off000155bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x155BC 5220 bytes
SHA-256: c5f763405ac4343dc167ebb8d7e2dc5516128a9b06f4077ee35e022d3e70526e
font_01_sfnt_off00016795.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16795 13268 bytes
SHA-256: f450cb95a8bb886653edd14e9eebd0b3f697b3c8e510ec87dd0f6eca93e0eefd