Malicious PDF — malware analysis report

Static analysis result for SHA-256 28240299437d592c…

MALICIOUS

PDF

102.0 KB Created: 2021-08-19 07:47:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 83f0e80b3e8d71ca1e4c7bba0814e765 SHA-1: 25f52fb97f578ef4a3addf7f8fadf74b21ad0dd6 SHA-256: 28240299437d592cd83cddcdefb3d205cc45c263f4a90864e602569bfdf10c60
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to manipulate search results or direct users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://iraneto.com/basefile/iranetocom/files/69486135705.pdf In PDF document text
    • http://nbpcpentecostalchurch.com/clients/65183/File/34752644301.pdfIn PDF document text
    • http://ypcalumni.com/clients/2/24/24042806289e0d450134266962f0a0d8/File/rekexugixalopomaduvuri.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1611cc9b190229---wolal.pdfIn PDF document text
    • https://brod-plovdiv.com/images/forefezazikutipizipa.pdfIn PDF document text
    • http://yeditepegumruk.com/userfiles/41984040390.pdfIn PDF document text
    • https://francemonde.news/UserFiles/file/samut.pdfIn PDF document text
    • http://www.mmalappeenranta.com/tiedostot/files/20677383965.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609afca7b8a62---56786560916.pdfIn PDF document text
    • https://papersacksfactory.ae/images/bulk_images/files/77055435064.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609fe571a408b---zikosajili.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160778955544d8---72214397157.pdfIn PDF document text
    • https://rasorestefano.it/file/45705285442.pdfIn PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160901fcaca713---rorikop.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/16114e19f79ff6---wexufegidolerizunix.pdfIn PDF document text
    • http://nail-free.com/ckfinder/userfiles/files/24461363538.pdfIn PDF document text
    • http://e-sportis.com/images/upload/33211692190.pdfIn PDF document text
    • http://cartopack.com/Images/file/xedew.pdfIn PDF document text
    • http://www.allatpatikapecs.hu/images/file/linojariwel.pdfIn PDF document text
    • http://nhasachnguyenvancu.com/Images_upload/files/31823871201.pdfIn PDF document text
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/144514ea58610111df1d1751ce5a9347/19849162562.pdfIn PDF document text
    • http://tahyuh.com/uploads/files/202108171022342017.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b338eeed295---25920200077.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/nisjgkt5vn6i2f1o0ej2u6ra08/zewobigij.pdfIn PDF document text
    • http://unsersohn.ch/images/file/22770528238.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=what+is+the+message+of+the+caucasian+chalk+circlePDF 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_off00012b32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B32 10968 bytes
SHA-256: 3d368cb29eb379151c6d80003f8116f880f21f1006b82725cebefee1f9a377fd
font_01_sfnt_off00014480.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14480 18096 bytes
SHA-256: 0c237760b2660f021efe547ab2e0eb6e8914bed43162e0831f4b10f0ca76c04c
font_02_sfnt_off000171db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x171DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1