Malicious PDF — malware analysis report

Static analysis result for SHA-256 e458c8dda33c4f13…

MALICIOUS

PDF

85.6 KB Created: 2021-09-14 10:17:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 52971d93e48fbdee4fb3e025f535bb22 SHA-1: 826f07c0bb84cb2656b97986595ac39081ebaf51 SHA-256: e458c8dda33c4f13e7b7af3393fe1b0297ce3621416353d743fb2243afb90cef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links, many pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users. ClamAV and ML classifiers also flagged this PDF as malicious, likely a phishing or trojan delivery mechanism. Although no scripts were explicitly extracted, the nature of the link farm suggests an attempt to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://yung-shun.com/userfiles/file/pumirame.pdf In PDF document text
    • http://primebrokeragetx.com/ckfinder/userfiles/files/9994632976.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/89754581056.pdfIn PDF document text
    • http://videofilm-tv.ru/content/File/25203553443.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/14a886e93fa2c018470f8d95d56bb853/14323721608.pdfIn PDF document text
    • http://siripanyalamphun.com/user_img/files/fekasajelez.pdfIn PDF document text
    • http://prestizhstroycompany.ru/SITE/files/editor/file/81706207783.pdfIn PDF document text
    • http://riversedgefm.com/files/file/wimajivexa.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/vc43aeh2uto0jog2654da5guf3/46406995796.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16138f7869d04b---kinebukosa.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/0ep45k3umr6ufpqgp03kd2ggfb/65058696506.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/20213781163.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9b17680aa---laturevesexakaxate.pdfIn PDF document text
    • http://ajitcoatings.com/uploads/wekarof.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e9692a591b---23042888074.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/t1p4f6jjd2oe2ri1oleitla905/41770418614.pdfIn PDF document text
    • https://godahoian.com/app/webroot/upload/files/37690149187.pdfIn PDF document text
    • https://ayurmitra.com/files/file/44315005524.pdfIn PDF document text
    • http://vizesblokk.hu/files/file/dapemi.pdfIn PDF document text
    • https://mimpishio1bet.net/contents/files/padadukoj.pdfIn PDF document text
    • https://pianotuningdarwin.com/userfiles/files/gagevuxegawovuru.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132c5a2b260c---kedixaxezo.pdfIn PDF document text
    • http://take114.kr/FileData/ckfinder/files/20210912_ED35336B6C3A747D.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/f7a9f78501c806a599e891288e0977cd/75398395939.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=text+new+apkPDF 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_off0000ecdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECDD 9960 bytes
SHA-256: 1b1609d42dffe0bff1d08ee3ecef83470189cf2c281933f14df3725849b9e32c
font_01_sfnt_off00010323.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10323 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B35 17632 bytes
SHA-256: a35caeceb14f9ec87921d177d5596dde51fe56bc063beaeec2447dc52ab78159