Malicious PDF — malware analysis report

Static analysis result for SHA-256 457a3aa38913874c…

MALICIOUS

PDF

79.9 KB Created: 2021-09-22 13:34:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f6e34a2d9ebe78d5f15ab60df426c4af SHA-1: 2c88ed9a2680241a8e3f2402684f45857b24ac45 SHA-256: 457a3aa38913874c027e161683692fbebada8b7fd6a47540299af9f210f19e37
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm directing to multiple compromised WordPress upload directories and other disposable hosting sites. The primary purpose appears to be directing users to malicious content hosted on these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://zemiigori.com/uploads/file/3491789965.pdf In PDF document text
    • http://khachsanmyngoc.com/upload/files/fawubutemagugixan.pdfIn PDF document text
    • http://www.nbc.com.vn/ckfinder/userfiles/files/31089168683.pdfIn PDF document text
    • http://turnwealthy.com/ckfinder/userfiles/files/bisamusumiwudowulawujufof.pdfIn PDF document text
    • http://htk2.altrodesign.eu/ckfinder/userfiles/files/lovegevataxovunox.pdfIn PDF document text
    • http://www.jfac.kr/ckfinder/userfiles/files/nosimibuvakuxugeguzofikel.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac325bb8bd---takakajubisipubaxoko.pdfIn PDF document text
    • http://skinct.com/upload_file/file/Fl202109020451085264.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f47096967---76270916880.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161347036f268a---fopolanufukaxavekotidoso.pdfIn PDF document text
    • http://parkergeneralcontractors.net/userfiles/file/30571853694.pdfIn PDF document text
    • http://obras.ru/sites/default/files/uploads/jumapuji.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/19385209777.pdfIn PDF document text
    • https://kmedebiyatgunleri.com/ckfinder/userfiles/files/71533433113.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/46665665943.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/wever.pdfIn PDF document text
    • http://vivo-mebel.ru/upload/file/wavifoxemoxejiv.pdfIn PDF document text
    • https://chanty.dacola.com/upload/files/7887132008.pdfIn PDF document text
    • https://izometal.net/mm/file/64098187093.pdfIn PDF document text
    • http://sziszolg.hu/editor_up/bimudikapo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=android+usb+settings+charge+onlyPDF 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_off0000d0b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0B4 10984 bytes
SHA-256: abbfaa23b76480e454f6ec589c6ecd3a4ed19108a60a9022fecb7332bce0e208
font_01_sfnt_off0000e9f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9F9 18264 bytes
SHA-256: 66feb5ee80ffd5ef49fd36caf01961bed7124062b81ccf81cb5d67f2496b044a
font_02_sfnt_off000119f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1