Malicious PDF — malware analysis report

Static analysis result for SHA-256 38c73b461c081999…

MALICIOUS

PDF

73.5 KB Created: 2021-09-16 05:57:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 640ac12be4cf7860351141e5ead72e9b SHA-1: e4466c155079e7423c5f8690f4a0453e5a854933 SHA-256: 38c73b461c08199939476078801ed6d3eeb749f5f92717a9769654a86e7a33a2
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://drafthe.ru/uplcv?utm_term=avengers+endgame+wallpaper+android
    • http://pileki.com/imgup/file/96583413293.pdf
    • https://bcbc3399.com/upload/files/93066225536.pdf
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/49bb3a2c567e9006baa2addbed4d838a/wukuj.pdf
    • http://fujavietnam.com/images/Download/27794450538.pdf
    • http://hcstonetw.com/uploads/files/202109011302553249.pdf
    • http://union.travel/ckfinder/userfiles/files/ripovimo.pdf
    • https://rachelrom.com/rescontent/file/71244439686.pdf
    • http://pierrevillers.fr/mairie_files/file/44589600599.pdf
    • https://khmernative-rice.com/userfiles/file/83185957882.pdf
    • https://atlantidegattico.it/file/bimorog.pdf
    • https://nakipoglugroup.com/upload/ckfinder/files/nafoparobu.pdf
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16131d33e4f0f0---13938107452.pdf
    • https://literie-depot.fr/UserFiles/file/nadujefofukofatufojepoki.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/2459f236a1f7411c2eaff36313f7e87a/xeganatajetorivir.pdf
    • https://812423.qqtogeljackpot2.com/contents/files/zuneluwedenewejovipow.pdf
    • http://jhdjt.com/images/upload/File/54064496484.pdf
    • http://motopujcovnateplice.cz/userfiles/file/nixawogudofopom.pdf
    • http://orbitsecurity.qa/pro_mvp_tech/uploads/file/70491146714.pdf
    • https://northwestconvention.cz/data/files/rekenubudatori.pdf
    • http://feminella.ro/upload/fck/21297425274.pdf
    • http://opakowania-loga.pl/zdjecia/fotki/file/veruvovo.pdf
    • http://ilonew.tasksplan.com/ckfinder/userfiles/files/nejagasiwosibivudu.pdf
    • https://tutorbolivia.com/userfiles/file/20818986378.pdf
    • http://diegogenna.it/userfiles/files/23537752937.pdf
    • https://bor-diing.com/upload/files/89543368107.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_off0000bc35.bin
50038dd9a4e976b79866fb4c2d1258f7cf01a5af2ceb4ba11d37364e3a9be188
pdf-font-stream PDF embedded font (sfnt) at offset 0xBC35 16632 bytes
font_01_sfnt_off0000e789.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE789 16792 bytes
font_02_sfnt_off0000ffa0.bin
39da2e2eb472f091e3c3fc03a7d814ffa361c8c3aae844762f6e4d6753d74174
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFA0 10768 bytes