Malicious PDF — malware analysis report

Static analysis result for SHA-256 73fa91b84c8d263f…

MALICIOUS

PDF

84.3 KB Created: 2021-08-31 23:16:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a6299ea4a2c4e23f762ba178c04bc265 SHA-1: 85d6e0ee60a27b5bd80867cbc9f51e20a86cb552 SHA-256: 73fa91b84c8d263fa2c78365ed82ca5dbc9a770a3a0fca695bb1080b9c713552
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. The PDF also functions as a link farm, pointing to multiple URLs hosted on potentially compromised WordPress sites, suggesting an attempt to redirect users to phishing or malware delivery sites. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://nomylo.ru/uplcv?utm_term=standard+form+science PDF link annotation
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a449e4c725f---77850988904.pdfIn PDF document text
    • http://ledspectrumthai.com/ckfinder/userfiles/files/46449089929.pdfIn PDF document text
    • https://krantiservice.com/ckfinder/userfiles/files/78243938429.pdfIn PDF document text
    • http://avstralianature.ru/ckfinder/userfiles/files/3874543160.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/48773036579.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/731a642b9c832f38143c1a590f8b03f6/68924208095.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1611c521c10c92---41203450332.pdfIn PDF document text
    • http://kingsfinancialconsulting.com/userfiles/file/kemuput.pdfIn PDF document text
    • http://agriturismofattorialucciano.com/ckfinder/userfiles/files/kamilisejisusifezuruwixak.pdfIn PDF document text
    • https://dmshospital.com/mm_engg/files/48684629329.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c95daea4d6b---mirufegonopokemusikiwu.pdfIn PDF document text
    • https://aravlicraft.com/cmsCart//upload/file/xojuxupanutuvidewudaneku.pdfIn PDF document text
    • https://sibois.eu/userfiles/file/98277290659.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/93dfa462199d8178cf4870bfea97d872/55902213875.pdfIn PDF document text
    • http://fsanaq.com/upload/file/210706054524679626ns52i0w6578h.pdfIn PDF document text
    • http://dailyliving.nl/ckfinder/userfiles/files/dasobodukemubef.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/v55edsar6vtgiql76ccjhj5hh1/72345579871.pdfIn PDF document text
    • http://ramseier-appenzell.ch/elrada/js/ckfinder/userfiles/files/femimufedineluv.pdfIn PDF document text
    • 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_off0000e40d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE40D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC24 10664 bytes
SHA-256: acc6f92752bea2ff25d9c4e37d4e5ee0a28349a74f5bf89e7505fb5f834ee08d
font_02_sfnt_off0001148c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1148C 18056 bytes
SHA-256: 7ca3fafbfb53470171acf55e1ce97b602e0945a67cff047eeb27e86c7876080a