Malicious PDF — malware analysis report

Static analysis result for SHA-256 81dc1c364f0e3e21…

MALICIOUS

PDF

92.3 KB Created: 2021-03-15 09:12:17 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: b52d138a054b2dc4cc7b7613961eec6c SHA-1: be7e7b36c82545ea89325abb600291f841fb8943 SHA-256: 81dc1c364f0e3e2180f7e8866c15d5a58bbfbdda805bb1471d87a351e0a0a1af
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting, indicating a link farm or phishing attempt. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the presence of numerous URLs and the overall structure point towards a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://seumenha.ru/strik?utm_term=sistema+endocrino+hormonal PDF link annotation
    • http://sellamorem.com/harry_potter_the_sorcerers_stone_mphi2rd.pdfIn PDF document text
    • https://vedixoba.weebly.com/uploads/1/3/4/8/134864822/tezelevasogo.pdfIn PDF document text
    • https://saxunada.weebly.com/uploads/1/3/4/8/134865385/0e7023b9f0.pdfIn PDF document text
    • https://lesofetu.weebly.com/uploads/1/3/1/3/131378838/nudepurigazis.pdfIn PDF document text
    • http://mkuu.club/80552480274b5nqz.pdfIn PDF document text
    • https://dapodufez.weebly.com/uploads/1/3/3/9/133997146/455610.pdfIn PDF document text
    • http://kartaidatodemeleri.com/24440226775pp299.pdfIn PDF document text
    • https://pajixuga.weebly.com/uploads/1/3/2/3/132303126/bf588.pdfIn PDF document text
    • https://dekukosozo.weebly.com/uploads/1/3/1/0/131070054/wadujatejujabamev.pdfIn PDF document text
    • https://biteledazuxol.weebly.com/uploads/1/3/4/3/134315761/lupufirodawu-sufeger.pdfIn PDF document text
    • http://pycnidwzxc.info/bimukukujovupavepzokhk.pdfIn PDF document text
    • http://medyayazilimtr.com/44576911985kwkiw.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://8f20b4bd-83f7-4a55-8c6f-e9501e2e061c.filesusr.com/ugd/c1c462_3d210be667e04a04809ad05ca0ab8cdd.pdf?index=trueIn PDF document text
    • http://fubavinexazixo.onlinewebshop.net/4th_grade_math_games_jeopardy.pdfIn PDF document text
    • http://suduxegowur.onlinewebshop.net/49318632710.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/42585363-cc3a-43a8-9929-f68494a1f23a/dog_art_wallpaper_hd_for_mobile.pdfIn PDF document text
    • https://b84c3727-5d5a-4c5d-9d5d-21cac87b3a69.filesusr.com/ugd/fdd6c2_44993e7b502e440d8494b44b75021232.pdf?index=trueIn PDF document text
    • https://76df98a8-3e94-4eee-a6f5-23e1de06049b.filesusr.com/ugd/54c74c_58b0f7ce74fe469b8e35e97fb4d00683.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/492d1759-8069-4659-a0ac-f73eb2425512/zozadaz.pdfIn PDF document text
    • https://9480ebe7-8096-4165-94d5-b35dd525e9f4.filesusr.com/ugd/07b43d_6f53d3b911454437a0fadae6157917e0.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/129eabe5-3cc9-409f-b84a-dc95eb0c6326/42420111826.pdfIn PDF document text
    • https://48bd7725-9370-4d18-884e-e75d7b70c9c4.filesusr.com/ugd/f241d9_83080fbee37345928104f6e5a8dbb090.pdf?index=trueIn 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_off000129a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129A0 5284 bytes
SHA-256: 436e7f12a2e3b57e6edbd4ae43b7b8615e40e66f7572910f9c97cbaccbcfa5ba
font_01_sfnt_off00013b66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B66 12128 bytes
SHA-256: 1bcbb5e894e85b003b00ecc2504d25452c876c4bdeff69a980fd69388f231686