Malicious PDF — malware analysis report

Static analysis result for SHA-256 52df4f81066c506b…

MALICIOUS

PDF

101.0 KB Created: 2021-07-19 06:07:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 781205c6338f5162418980b5cd9141e6 SHA-1: a0dbbca811231278bf767ea804a82628ae2dc3cb SHA-256: 52df4f81066c506bfc833fed9636e2f0492d26a0f26cb0a3671cd3dc81cb850c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of external links, many of which point to compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to direct users to phishing or malware distribution sites. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9923

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://www.synagoge-stommeln.de/ckfinder/userfiles/files/8354229262.pdf In PDF document text
    • http://petraifevronii.ru/ckfinder/userfiles/files/tibumise.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/2106ad7af45d99967174f416d77cdf9b/balopaju.pdfIn PDF document text
    • http://bendhigh1970.com/clients/1/10/106e6567aa8bd3cecf4080670b11bd10/File/39883275668.pdfIn PDF document text
    • http://angelofthewinds.net/ckfinder/userfiles/files/99081840493.pdfIn PDF document text
    • http://beveragesgs.com/userfiles/file/72506980553.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160dba9524a7c8---61468228383.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076abd51f8a2---wonararop.pdfIn PDF document text
    • https://guclupin.com/calisma2/files/uploads/tewifadujis.pdfIn PDF document text
    • http://valleypainclinic.org/userfiles/file/32225698838.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/f4256b6972d1a4cbd7c90f2770464af1/29908224673.pdfIn PDF document text
    • https://folklorebridge.eu/uploads/pictures/files/vuwikobegoze.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/b1d012f18374c27dbd61267c50e9efd6/79236560434.pdfIn PDF document text
    • http://aihyang.com/userfiles/file/39032522146.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/68e2d6d2ce681d5428ee753d843be609/jusolalipupuvelome.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160dbcbc8cc527---30420701300.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c32afeabd1---jubugokabifazuvoti.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bb817097f23---61135967508.pdfIn PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c35f4e2dac4---54621221403.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/xuminowidub.pdfIn PDF document text
    • https://suprizpin.com/calisma2/files/uploads/bovenutegodipo.pdfIn PDF document text
    • https://sunarchegypt.com/userfiles/file/60532079319.pdfIn PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/55251916145.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b773e3478d3---88465666597.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/9b5029d4eb4de2294c03b00b18729d41/miniweburuboxa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=relative+frequency+distribution+formulaPDF 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_off00011ff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF5 11248 bytes
SHA-256: f00656dae2cd5ffcf5da3eb6b013b63afcc6435c4000ac9ff88d3518e3dd5b19
font_01_sfnt_off00013a2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A2A 20052 bytes
SHA-256: 7932912af8362bb18055a131c7c0283339fdd2d18c9f353c7e72132cc6534e9f
font_02_sfnt_off00016e24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16E24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1