Malicious PDF — malware analysis report

Static analysis result for SHA-256 327090881a3f61c1…

MALICIOUS

PDF

73.3 KB Created: 2021-09-20 06:12:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 40fad648577ae82afabcb6bafa114bc3 SHA-1: 72a41c92324c66bdc37970c658c24f98a3eb9e8f SHA-256: 327090881a3f61c1e4b7c34b0ee38eef78d149ae8c9b40f59dcdc76eec18c160
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous URLs pointing to potentially compromised websites and other PDF files. The presence of multiple 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics strongly indicates a malicious intent to redirect users through a network of dubious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://sireny.net/share/files/dumixodoxalunopef.pdf In PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141ebcb60225---pozakazejusutufodaseja.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/44746635200.pdfIn PDF document text
    • http://thumpamonpally.com/userfiles/file/kutozitelotokuxinaki.pdfIn PDF document text
    • http://yalcinsezer.com/upload/ckfinder/files/75504237214.pdfIn PDF document text
    • http://xn--2osv9pt2jfpt.com/uploadfiles/files/87529914341.pdfIn PDF document text
    • http://elcivan.com/admin/UserFiles/file/8245068495.pdfIn PDF document text
    • http://revistaspontan.ro/assets/ckfinder/core/connector/php/uploads/files/66486041187.pdfIn PDF document text
    • http://www.scsk12.org/policy/files/files/getez.pdfIn PDF document text
    • https://csn-alliance.com/data/files/nosisamukuzusurosojus.pdfIn PDF document text
    • http://xn--80aafmoni2biho.xn--p1ai/admin/ckfinder/userfiles/files/xelubumede.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161324c9e8f0e1---nazavesoxukenokusova.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/161348ce5b3a4a---kegimuwasorituxumox.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16136ab22f2a43---46451159181.pdfIn PDF document text
    • https://basealimentare.it/webroot/files/fck_uploads/File/54213925536.pdfIn PDF document text
    • http://alcantara.cz/data/file/80715571646.pdfIn PDF document text
    • https://mannerfeltdesignteam.se/ckfinder/userfiles/files/jijeluzewajunonemapisota.pdfIn PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/kalesuxij.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/virijonukutevezupakewefi.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/faresozir.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/50543420343.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/161405b394b57c---26263376420.pdfIn PDF document text
    • http://odessawa.com/userfiles/file/16101348105.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/nomigako.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=song+going+on+a+bear+hunt+lyricsPDF link annotation
    • 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_off0000bbab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d3bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3BD 16492 bytes
SHA-256: 27f4ec57727b3947f424a57b2e2ae953c2be3dd9a0e1aa313c09232c3250da92
font_02_sfnt_off0000fe2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE2D 10940 bytes
SHA-256: 1c0db2f61aa54089e370844f9129ccbb71de2816849d1b5eecee889876aa1fbe