Malicious PDF — malware analysis report

Static analysis result for SHA-256 b53706b365f7a816…

MALICIOUS

PDF

73.9 KB Created: 2021-09-24 02:09:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2191647aa6d89db12ecfd9e39b6d0a01 SHA-1: 994f6b52d1c805dfbe793884c9bb6645b9d5ad24 SHA-256: b53706b365f7a816857437eb62dd9da29d6e0350f10d3df7a55dfb1c52b0ed2e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Numerous URLs were extracted, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, suggesting it serves primarily as a container for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://wastran.ru/uplcv?utm_term=android+open+email+programmatically PDF link annotation
    • http://slovbau.sk/test/userfiles/file/99488271065.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/d1d9965add8cb37645ce2794fd8c5f96/56410635790.pdfIn PDF document text
    • https://anjingliar2.com/contents/files/58223590853.pdfIn PDF document text
    • http://taemyung.com/data/upload/file/zuvezijulat.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16136962adbb2f---81941527346.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/kumaburi.pdfIn PDF document text
    • http://shqinze.net/admin/upimg/file///35507623500.pdfIn PDF document text
    • http://motolargo.pl/userfiles/file/15220894328.pdfIn PDF document text
    • https://skykharchono.mn/editor/files/4982121802.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1614679eb5696f---xuxozijirosuladodat.pdfIn PDF document text
    • https://brawlcall.com/ckfinder/userfiles/files/59084027060.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/161497d9f4e303---ximavevasaxiwemuk.pdfIn PDF document text
    • http://restaurant-lyons.fr/userfiles/file/73783492208.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/6211518397.pdfIn PDF document text
    • http://lmleadmanagement.com/userfiles/files/47126025168.pdfIn PDF document text
    • http://ps-chiptuning.hu/userfiles/files/rategivewanas.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210913210710.pdfIn PDF document text
    • https://stl-log.com/htdocs/cljr/data/files/61018397029.pdfIn PDF document text
    • https://bompentax.com/quangbasanpham/app/webroot/upload/image/files/jonopiva.pdfIn PDF document text
    • https://seeyounow.net/userfiles/file/nexixurazinevilatumibanob.pdfIn PDF document text
    • http://eternaseguros.net/files/files/39493078950.pdfIn PDF document text
    • http://paolacaone.eu/userfiles/files/godojivagunigun.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/nuvomukitanofesaj.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/zoretijujikojura.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b98e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB98E 10784 bytes
SHA-256: 1ce129c44f38b86d1eabb7707c5683130c70c39261e47622b1844e095f77d177
font_01_sfnt_off0000d22d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD22D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ea3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA3F 17716 bytes
SHA-256: 0f77f2a3f80dca6da3554a55d2a5f2cb9f78df78f1c7ba0d7d927b4571db8a95