Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c8851ebce904883…

MALICIOUS

PDF

81.0 KB Created: 2021-05-16 03:55:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: fbca8d2757aeca40af3cf54d96827920 SHA-1: e1a31c4231f59427fe7ccff3413eebc112f2bc56 SHA-256: 6c8851ebce90488346d1a67db7dd6eb933171b50167e317e2e481e4d29d4c3ce
244 Risk Score

Malware Insights

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

This PDF file contains a large number of embedded links, many of which point to disposable hosting or redirector infrastructure, indicating a link farm designed to lead users to malicious content. The primary malicious URL identified is dafemum.ru, which is flagged as a known malicious redirector. The ML classifier and ClamAV detection strongly support the malicious nature of this document.

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
  • 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://dafemum.ru/strik?utm_term=used+ford+mustang+shelby+gt350+for+sale+near+me In PDF document text
    • https://cdn.sqhk.co/ruvonusebex/giaBgjs/34905021337.pdfIn PDF document text
    • http://moxegelubopidi.sportsontheweb.net/adverb_clauses_exercises_with_answers.pdfIn PDF document text
    • http://lobulezinovux.medianewsonline.com/riduttori_epicicloidali_bonfiglioli_catalogo.pdfIn PDF document text
    • http://pozufopajosel.mypressonline.com/cold_war_summary_of_events.pdfIn PDF document text
    • https://cdn.sqhk.co/zezinojox/fXhhif1/kedorowenotu.pdfIn PDF document text
    • http://wejowadizabudex.mypressonline.com/pupogavagenobipefonuri.pdfIn PDF document text
    • https://cdn.sqhk.co/bajipugotox/8KgcjcW/geo_bookmark_example.pdfIn PDF document text
    • https://cdn.sqhk.co/fupipevu/whh8jca/tv_guide_now_sydney.pdfIn PDF document text
    • https://cdn.sqhk.co/dodamewope/ciefVjh/dotikirujatorenogozeva.pdfIn PDF document text
    • http://lenuvivureropi.scienceontheweb.net/is_cyberpunk_2077_exclusive_to_xbox.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://40e214c1-1950-44e8-a195-e2c6eeb23253.filesusr.com/ugd/a517f4_8d2929e7c35948539af1ac13f6d9186d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1101ea08-e683-4e43-9b47-67413bdb8473/how_to_teach_seniors.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b14905f0-02f6-4df3-98cd-aa85f2a6f453/how_to_update_adobe_flash_player_plugin_in_chrome.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9d6e7d1b-e8d6-4b8a-8f28-52f0516f778d/36145165841.pdfIn PDF document text
    • https://b20aee1f-b1b7-4e4e-be5e-d884e4ece670.filesusr.com/ugd/10e3af_42c764499a9d4d278d4eadb3900c4ee9.pdf?index=trueIn PDF document text
    • https://abbf68a8-5b21-4996-91be-11266bd273ed.filesusr.com/ugd/9374a7_d289a7e33cd2460083b36b1c68c3a0df.pdf?index=trueIn PDF document text
    • http://suwuriru.onlinewebshop.net/sowejesurixagodejofud.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/18a63452-a95b-4548-8d63-d3dca0861051/samsung_front_load_washer_pedestal_drawer_removal.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b77153ad-3f26-46a7-8c3b-92897ad1c728/52884011320.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/32ed6442-5492-4159-b9b4-70306d3976d7/jerotekozi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98630b98-d7fe-4fdd-bf9d-1bcb2a3dda0b/starbucks_barista_espresso_machine_troubleshooting.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_off0000fc78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC78 5984 bytes
SHA-256: 03c98ee72fddf3711bf51ef460429b420a66382a61ebe291b1b1594aefce35f3
font_01_sfnt_off000110b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110B2 11116 bytes
SHA-256: 5c81c91e1722aa5d6721c74d2a8af09a69b1c29831690220967e4cd29fe18c53