Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc78bea40905848a…

MALICIOUS

PDF

91.5 KB Created: 2021-09-02 07:28:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b0ad6f5d2d7b3acceed476ec4f3600d6 SHA-1: e3a637d30618568c5231f3deb6ae32ad3881f6c6 SHA-256: dc78bea40905848af5e6a5f4996c9284ebcd78ded2f17cdee110ffbf8659c0df
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous external URLs pointing to potentially compromised websites or disposable hosting. The document body is heavily obfuscated, preventing analysis of its direct content, but the overall structure and heuristic firings strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 6

  • 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 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://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/rimujetituzejaxutame.pdf In PDF document text
    • https://springkasteelhuren.be/userfiles/file/678319710.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a411afe4a---vixijilubetixofibole.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/61411f4eab917b3f8fe0b0b83cb22c79/49898841222.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160929e2797eee---fogil.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/f92405783e4ecc298414b3ccc67dc006/sasuwoluxesaraxi.pdfIn PDF document text
    • https://visualarchive.bg/files/xazefex.pdfIn PDF document text
    • http://superpart.com/files/63271981996.pdfIn PDF document text
    • https://acronimocostanzo.com/userfiles/file/88679361460.pdfIn PDF document text
    • http://wienbildarchiv.com/upload_files/files/wufefibikeviko.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/ea6b06314d07d1ffe584ef0d691d9361/betibasajanimipisiji.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/2be8fa81b60b45e365d24e6342dc55fb/kogosejudezalemokudokib.pdfIn PDF document text
    • https://best-label.com/upload/files/90528740182.pdfIn PDF document text
    • http://goteneplast.se/files/images/file/97640708194.pdfIn PDF document text
    • https://rcot.org/userfiles/file/gozobebabimepep.pdfIn PDF document text
    • https://eurouniversal.eu/ckfinder/userfiles/files/13058979613.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/a62bbfe69886a346a53c9d15338c509e/83679846661.pdfIn PDF document text
    • https://pergamine.com/ckfinder/userfiles/files/61230790486.pdfIn PDF document text
    • http://namuvaldymas.lt/userfiles/file/goxuloxagimomenatexisuwi.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/zimivilox.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16080221f2464e---10918298194.pdfIn PDF document text
    • http://fletcherfamilyreunion.org/clients/52745/File/wagusigirirasak.pdfIn PDF document text
    • https://hyosung-gulf.com/uploads/file/89883915526.pdfIn PDF document text
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/nusode.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/bofizevejilenodera.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=free+medal+of+honorPDF 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_off00010068.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10068 17864 bytes
SHA-256: 704d254df73b9af630c685b4364c8a98babdc9ec6676bce014c1c26176b32cf9
font_01_sfnt_off00012efc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014713.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14713 10236 bytes
SHA-256: 5df3460b66c07d09beded63e060a8054e0fa7e0a4d8b44db39336bed76746875