Malicious PDF — malware analysis report

Static analysis result for SHA-256 b82e54eef511760a…

MALICIOUS

PDF

84.0 KB Created: 2021-08-23 15:36:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a549e6d3323712467c2d20434b4d643e SHA-1: 0103e0e01482a1e4751e19de0f702bdd03363058 SHA-256: b82e54eef511760a6691b1bbb0c956eda8d549711f7148d2f2ec1720c4d2b0fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple compromised websites, many of which host PDF files. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics suggests a tactic to obscure the true destination or leverage compromised infrastructure. While no scripts were explicitly extracted, the PDF structure itself likely facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://oncetrabzon.com/resimler/files/fubapimajaxutegapero.pdf In PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/16108f0a65c205---41046562832.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/30263502017.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/8c2c6b3cb34eeb95a41b7d8277ba77a0/4113165962.pdfIn PDF document text
    • https://fceresources.com/ckfinder/userfiles/files/16210459042.pdfIn PDF document text
    • http://stellar.ru/ckfinder/userfiles/files/40406455921.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/29019328954.pdfIn PDF document text
    • https://marathonlaval.com/userfiles/files/60372862168.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4f45d13180---73970104976.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/485a88b6528daa0d11d44a2be1195b25/7291555609.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/6eafa419f1741f4e616e183008ca4ba2/zemilizigozixopexakataxi.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d504f99bfd---18327861945.pdfIn PDF document text
    • http://mashtalkandil.com/userfiles/file/bobojedujupemunij.pdfIn PDF document text
    • http://expertsystemgroup.com/file_media/file_image/file/tivame.pdfIn PDF document text
    • http://dentherapia.hu/files/file/lunikiw.pdfIn PDF document text
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/lh4m3efgk25bt8g785imlkq1tt/77637705045.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a864bce6eb8---68429919991.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1342d7ae17---24977920908.pdfIn PDF document text
    • http://maility.pl/_ADRESuserfiles/file/pilamav.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609834e67b04b---99731196263.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/99122646694.pdfIn PDF document text
    • http://kppzp.pl/userfiles/file/19658703018.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/61715658063.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/bamew.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/efl06g5d7554j37fg3b292939j/roboxibuzosaduzexisetinot.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+write+a+cv+for+study+abroadPDF 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_off0000e2d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fae5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE5 17656 bytes
SHA-256: 5ca18f16e462d198bada3cf515a2872c1cc1fee1117032f71f68b8e9fe852efe
font_02_sfnt_off00012911.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12911 10816 bytes
SHA-256: 21e71b2555c4e9c49e0e65c2b5c45088a484cfa6691455ef8f153ddabf272d81