Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b6db4eda0f2f5d0…

MALICIOUS

PDF

81.5 KB Created: 2021-09-03 05:29:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d43b42ac8c9389ac2ba3c25c2d5da417 SHA-1: d66cf0f509d6ec888932a5a6698355d271d1b9d3 SHA-256: 5b6db4eda0f2f5d009cb2e474302a97ff17d1e32d426720478aaaf0d0e50324f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The document functions as a link farm, directing users to numerous PDF files hosted on various domains, some of which are identified as compromised or disposable. The presence of external URI links and the overall structure suggest an attempt to distribute malicious content or phish for information through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://kerama.altrodesign.eu/ckfinder/userfiles/files/nujexuto.pdf
    • http://hanboo.cn/Uploads/file/2021071707582470554.pdf
    • http://amandatravel.com/userfiles/file/tupogerixifijabanak.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161004318c4d0e---72078317771.pdf
    • https://dgssu.com/upfolder/e/files/20210810075047.pdf
    • http://fli.edu.mn/ckfinder/userfiles/files/9056236427.pdf
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/5f33f156bd2c0a858de7bd8a5c808569/14880718096.pdf
    • http://sushimura1.com/uploads/files/3201935096.pdf
    • http://huntland.hu/upload/file/lemubefifawobegunaku.pdf
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a24fbd84ec7---7027238511.pdf
    • http://fqcycpa.com/jingkelun/userfiles/files/20210610013438.pdf
    • http://www.anclupnapoli.it/userfiles/file/gojilitamuta.pdf
    • https://clickkedai.com/userfiles/file/vukexorezijafasu.pdf
    • http://ulleungroadtour.com/FileData/ckfinder/files/20210725_1C197216476954AD.pdf
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b08f37b5fce---76843356925.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a4e07f75e92---45374963162.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a3caf9c690a---rijelefetojefiwamara.pdf
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/daad91650526bcb6f92036c7d9f994a6/xalojiwuwurasozize.pdf
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/1abf70da0635fabf3ecb6d27b7ae5e6a/jufefubirimeseve.pdf
    • http://hindel-relax.ch/ckfinder/userfiles/files/dafunisojojisivepage.pdf
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160737d89b2b8c---rupunobitixuniroze.pdf
    • https://ajur.rest/uploads/userfiles/file/24699425239.pdf
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607120cf42f11---16031415326.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=modern+x86+assembly+language+programming+pdf+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d5a8.bin
0c57be6af3ab55bb3830ad47d0c40b9924c58520629ff698d93299bbc2cfcd8e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A8 18048 bytes
font_01_sfnt_off0001044f.bin
cd756d0e9557480325668ea3adc9224575d38c94471e8cf5d08bccd6d103885e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1044F 11652 bytes
font_02_sfnt_off00011fb6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FB6 16792 bytes