Malicious PDF — malware analysis report

Static analysis result for SHA-256 5373b166bc4d3561…

MALICIOUS

PDF

85.5 KB Created: 2021-07-21 03:29:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: c51006a41e7c33529f15b9b2f09d9c2c SHA-1: 458ce6ad759ab86b5b8173b6a072fbb3acf80d9f SHA-256: 5373b166bc4d35614482223c3816c64808345e7e802cf88ebb35c9c9ab70728c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous unknown PDF files hosted on compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the structure and embedded URLs are indicative of a malicious document, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609002ad0e001---kewilalarobibi.pdf In PDF document text
    • http://jiangsutravel.kr/userfiles/files/20210619_091739.pdfIn PDF document text
    • http://ergo-logo-bamberg.de/userfiles/file/47043722656.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/6208ab8afa0110ce7964813bfbbb7dfd/rosutubuwabofojume.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/8927166495.pdfIn PDF document text
    • https://bursac.net/userfiles/file/13036274499.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/2926f9afc0101244803b96b1799bebe2/jolopog.pdfIn PDF document text
    • https://ecohort.info/userfiles/files/30035594438.pdfIn PDF document text
    • https://transport-vehicules.fr/userfiles/file/54636367643.pdfIn PDF document text
    • https://247christianity.org/fckeditor/userfiles/file/635455132941625417114.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/zanawipofisatudebun.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/ea3nbmr4tfs4n33h9aj0hvppt2/2560344150.pdfIn PDF document text
    • http://zonazero.es/userfiles/file/54766100297.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/52694088890.pdfIn PDF document text
    • http://bogelaipigeon.com/upload/file/34374329998.pdfIn PDF document text
    • https://gomaihoa.net/upload/files/29316994933.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/db8d32d34c0ddfdda5435d308fbcfcaa/ribame.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d608132280---32068863143.pdfIn PDF document text
    • https://novzelandiya.ru/ckfinder/userfiles/files/75639982535.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1609fb39250509---konigasagemudagokog.pdfIn PDF document text
    • http://vallovin.it/userfiles/files/vofufaliva.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/8ae8b300ebf4ebb1c94c9f2be3b753b9/meragitovogi.pdfIn PDF document text
    • http://carsonandchain-ip.com/userfiles/file/1452485474.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+long+can+cooked+chicken+stay+out+at+room+temperaturePDF 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_off0000e8cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8CB 11344 bytes
SHA-256: d9d115788f6f2fe6f2a317410ed8b5b2fbb3ebe46325f82817e2a5bce063f6ca
font_01_sfnt_off0001032a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1032A 16596 bytes
SHA-256: 7142dfed3262220ba32555672211374ae9f8a6f283a87ca3c469d0eb6c092c31
font_02_sfnt_off00012e40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1