Malicious PDF — malware analysis report

Static analysis result for SHA-256 191e5624c8317fa0…

MALICIOUS

PDF

86.5 KB Created: 2021-09-08 01:45:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 404cd323d40a6d853a004e8b3305f6f4 SHA-1: 407045a4d316ef21992a85610ee245dbd9f92f22 SHA-256: 191e5624c8317fa005afc6556fdcce7c3b94f28fe5d77cc8449d85783a573780
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm designed to redirect users. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a pattern of distributing malicious content through these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://coretry.ru/uplcv?utm_term=libro+de+rimas+y+coplas+para+ni%C3%B1os+pdf+gratis
    • https://mimpisiluman.com/contents//files/38286726458.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16081e5986a43f---rowarawusefazi.pdf
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c415c6e292f---sufisoxovan.pdf
    • https://nhathuydesign.com/wp-content/plugins/super-forms/uploads/php/files/33vk39a8c4ekf7riududdi04ti/9606133150.pdf
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608227bebfa06---durexisibadabedapus.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/6ju7mgbuc0lsq8r9orjumdikp2/lubowabazoxoxosaw.pdf
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607f147071609---99363453687.pdf
    • http://albertopizzetti.it/userfiles/files/tunog.pdf
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c80ecf2b8---sepowinaxekusiwagix.pdf
    • http://cattaneoarchitetti.it/userfiles/files/43612714338.pdf
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/53474a89b68fc845495c5f3ddf48b837/vufarewagalekobuzu.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1609067c706ef2---luzimol.pdf
    • http://healhumanity.foundation/userfiles/file/82638179860.pdf
    • http://www.apsetedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0a5f2ed14---57146400716.pdf
    • http://goldnumber.info/userfiles/file/zoberodeka.pdf
    • http://hongsung114.com/files/fckeditor/file/60197381647.pdf
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/f46a11654a8b64ee2b2564cf1376efeb/89782995998.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba2806a98ef---57867198176.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160af7801f2b75---9749974880.pdf
    • http://519pf.com/userfiles/files/68517087115.pdf
    • http://hdurmuslar.com/images_upload/files/vobamepunaduriluziri.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/be5653e0dc7430108508b1fe8e784670/dogetixixojukeju.pdf
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/fakdo1q1g3ln5n6q29jrh6p8r5/gemakipepifugokedub.pdf
    • http://datev.hu/ckfinder/userfiles/files/99973460346.pdf
    • http://aihyang.com/userfiles/file/70961500214.pdf
    • 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_off0000e523.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE523 16792 bytes
font_01_sfnt_off0000fd35.bin
63b9720142325fd688dc575cd4d4c5da0282f95c21bb30599000a709a87af2b4
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD35 19188 bytes
font_02_sfnt_off00012ef1.bin
7de18ece1324bc871b110a97d13693d7a8061244567f0827d62cb3f770399e3b
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EF1 11380 bytes