Malicious PDF — malware analysis report

Static analysis result for SHA-256 c36d238cf7cf9934…

MALICIOUS

PDF

76.7 KB Created: 2021-09-22 09:33:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ce86a22b02a62a734d60b5d04ce7f7f2 SHA-1: db610d121fbe1978c819d6a1b4c3c55af6a1086f SHA-256: c36d238cf7cf993473308b8e7927ce819fd399d901eee41b1f35285b1089ca1c
142 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external links, including one pointing to 'infrive.ru', suggesting an attempt to download or redirect to malicious content. The presence of a 'download button' heuristic and ClamAV detection as 'Pdf.Phishing.Trojan' strongly indicates a phishing or malware distribution campaign. The ML classifier's high score further supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://infrive.ru/uplcv?utm_term=happy+birthday+krishna+cake+gif PDF link annotation
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16136e8fd8ce90---zapidoveveliwaxifizap.pdfIn PDF document text
    • http://worldcar.jp/userfiles/files/jakagewalugexir.pdfIn PDF document text
    • http://dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/92474679178.pdfIn PDF document text
    • http://machinesupplier.cn/data/product/file/202192_11130_983.pdfIn PDF document text
    • https://reklama71.ru/upload_picture/lomikexuwemogojusowotewa.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/09/09/50299559346.pdfIn PDF document text
    • http://dienlanhhuubinh.com/upload/files/bixanakotamuvali.pdfIn PDF document text
    • http://aptekainternetowa.net/_mdm_apteki/file/rezamewe.pdfIn PDF document text
    • https://zaindu.drogomedia.com/files/galeria/files/nubebemesakovatekenos.pdfIn PDF document text
    • http://formel1vermietung.de/userfiles/file/43784357423.pdfIn PDF document text
    • https://arerp.kr/data/file///91192214398.pdfIn PDF document text
    • http://sun-marche.com/app/webroot/js/ckfinder/userfiles/files/togejirolibuwadaz.pdfIn PDF document text
    • http://newtarrytowndeli.com/uploads/files/92825698662.pdfIn PDF document text
    • http://bojovesporty.cz/userfiles/file/70672523834.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a8333d550---89605498219.pdfIn PDF document text
    • https://nikunjfoundation.org/ckfinder/userfiles/files/97723866040.pdfIn PDF document text
    • http://armiikrajowej36.pl/public/upload/ckfinder/userfiles/files/44541297398.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/tafozeraxutasesegaxojaj.pdfIn PDF document text
    • https://whatshoulditcostme.com/userfiles/file/78554547054.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/49160282909.pdfIn PDF document text
    • https://icnj.net/ckeditor/ckfinder/userfiles/files/zefenuled.pdfIn PDF document text
    • https://hgb.se/filer/file/79582928478.pdfIn PDF document text
    • https://leciv.fr/uploads/FCK_files/file/todinugoso.pdfIn PDF document text
    • https://apaman.ti-am.jp/js/ckfinder/userfiles/files/61188749419.pdfIn PDF document text
    • http://tetrafluoro.com/upload/files/39975197515.pdfIn PDF document text
    • https://alixdemassy.fr/userfiles/file/buseti.pdfIn PDF document text
    • http://techbico.vn/uploads/image/files/3034167196.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_off0000c83c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC83C 16960 bytes
SHA-256: 3a2d8edc1f1a98d576dbd244114a649e319605b3f41b01fe6ff2538abecd401b
font_01_sfnt_off0000f406.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF406 11068 bytes
SHA-256: 8a6030f473fa2e1752a1125325f37cca67c9bc23b53c8da85b446d54956db23d
font_02_sfnt_off00010d57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1