Malicious PDF — malware analysis report

Static analysis result for SHA-256 33f6aff331e66813…

MALICIOUS

PDF

79.3 KB Created: 2021-02-25 19:45:21 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 06ebdd3c1ebb98622e0d36fc361e9034 SHA-1: b080c9dd0cc70b16cc2544a3ca653d374a1e99f7 SHA-256: 33f6aff331e668132e12a03b92338cd8086650415f9370b17dc88a9a61fea46a
184 Risk Score

Malware Insights

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

The PDF contains embedded links pointing to known malicious redirector infrastructure, specifically 'https://yafferge.ru/award?keyword=foscam+fi9821w+v2+firmware+upgrade+fail'. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure related to firmware upgrades, designed to trick users into clicking the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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 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://yafferge.ru/award?keyword=foscam+fi9821w+v2+firmware+upgrade+fail In PDF document text
    • http://sevagawos.getenjoyment.net/sirew.pdfIn PDF document text
    • http://umkatrade.ru/bafojesevipakawegesemapiqj53z.pdfIn PDF document text
    • http://zumewidife.mygamesonline.org/letaderakugepis.pdfIn PDF document text
    • http://taforojujutusig.mygamesonline.org/68290256435.pdfIn PDF document text
    • http://numulul.mygamesonline.org/lista_tascon_excel.pdfIn PDF document text
    • http://zimezobot.getenjoyment.net/82826580970.pdfIn PDF document text
    • http://instacopyrighthelpteam.com/contoh_performance_bond_adalahlh8l5.pdfIn PDF document text
    • http://dewisazovuvoxi.mywebcommunity.org/crossfit_wod_list.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://ruvesigokusi.epizy.com/jitterbug_flip_phone_user_guide.pdfIn PDF document text
    • http://fegumipidibig.rf.gd/9351400545.pdfIn PDF document text
    • http://ruxatavebokoj.epizy.com/scratch_junior_per_pc.pdfIn PDF document text
    • http://jumepenitujox.atwebpages.com/java_j2ee_interview_questions_and_answers_for_10_years_experience.pdfIn PDF document text
    • http://ralirajuz.atwebpages.com/bemeluvovozoxewiposokelow.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_off0000f118.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF118 6116 bytes
SHA-256: 2fb61a1a4055937e9d84bff3c8672e420f0eb8970ffeb911a06282b14977e43d
font_01_sfnt_off000105f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F1 12924 bytes
SHA-256: 95052531e58a250cebebe78fec493635501ae2366bd22443d3acb7817fea0c70