Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecf36ad4dc9bac1e…

MALICIOUS

PDF

72.5 KB Created: 2021-06-04 02:24:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: fbc16366929c84f8103669e5a935a106 SHA-1: b25b9f0fe6edb9b09682ca9500116fed004f8613 SHA-256: ecf36ad4dc9bac1ee3fa933b9709d9b0770f0b4c3e4665ce5ba2ccf4c1f6386b
186 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically as a phishing or trojan distribution attempt. It contains a large number of external links, many hosted on disposable domains, indicating a link farm designed to manipulate search engine results or direct users to malicious content. The embedded URLs and the document body, despite being heavily obfuscated, suggest an attempt to lure users to external sites under the pretext of providing information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://coretry.ru/pbw?utm_term=how+to+calibrate+a+convection+oven PDF link annotation
    • https://bevabuje.weebly.com/uploads/1/3/4/8/134897483/1451011.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365662/normal_604cd8e43ea8b.pdfIn PDF document text
    • https://jesaguxofugu.weebly.com/uploads/1/3/4/6/134659129/virofolimo-nuvetix-movesirawimufu.pdfIn PDF document text
    • https://sutenemumam.weebly.com/uploads/1/3/5/3/135323571/ketelifolusunefe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448330/normal_600a518929fe7.pdfIn PDF document text
    • https://gazesomudari.weebly.com/uploads/1/3/1/0/131070071/8925799.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4492286/normal_6008e9509c7a6.pdfIn PDF document text
    • https://fotelosalif.weebly.com/uploads/1/3/4/4/134463398/nudediduwur_xusiketig.pdfIn PDF document text
    • https://zarokosa.weebly.com/uploads/1/3/5/3/135300057/bomuja_sanikoxalobelep_biralazo.pdfIn PDF document text
    • https://luvuzinek.weebly.com/uploads/1/3/4/5/134502649/7241df2.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/7a393054-acee-49af-bac1-09be73022fba/doromejobebosolademoxoji.pdfIn PDF document text
    • http://jutifakukap.pbworks.com/f/fanajok.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2765f5f9-747e-41bb-9b2a-3a5c38e94d82/english_vocabulary_meaning_in_tamil.pdfIn PDF document text
    • http://wikitaxif.pbworks.com/w/file/fetch/144580206/tudem_5.snf_matematik_soru_bankas_indir.pdfIn PDF document text
    • http://siwuromo.pbworks.com/f/how_many_calories_do_you_burn_in_1_hour_of_vinyasa_yoga.pdfIn PDF document text
    • http://wuwolufit.pbworks.com/w/file/fetch/144578124/reasons_why_my_firestick_remote_not_working.pdfIn PDF document text
    • http://vibevekofano.pbworks.com/w/file/fetch/144426204/16981267529.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e03d35ac-ec2d-487c-ab72-29075cbe47ed/wewijejudatababi.pdfIn PDF document text
    • http://wojipag.pbworks.com/f/67984465250.pdfIn PDF document text
    • http://foziwedugumu.pbworks.com/f/77776924454.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_off0000dfbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFBE 4868 bytes
SHA-256: 041704694318e6eb80c780e62c80dd8c3e5146a9ccc5934263acb1cae94a8d99
font_01_sfnt_off0000f070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF070 10660 bytes
SHA-256: 6063d748adf408a2f4d5b8fa1eccfaed83efac4876cfa7647023f200c6acad09