Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5c031a249c8bcd1…

MALICIOUS

PDF

115.3 KB Created: 2021-07-07 10:53:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: a0230163c7f054331b34990fc862540e SHA-1: 24c3040915033c0a5f32d61f40a9f956f9c4ae82 SHA-256: f5c031a249c8bcd15d5e8525bd944e7ba3404a5c32595dc967681495729414f2
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to potentially compromised websites, a common tactic for distributing malware or conducting phishing. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user consumption but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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.majbrno.cz/uploads/files/dewukijudek.pdf In PDF document text
    • http://mujeresenmovimientoplus.com/userfiles/file/8399491373.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/ce6f0cf108b7263e559e298c9e43f936/polejugano.pdfIn PDF document text
    • https://ols.lighting/wp-content/plugins/super-forms/uploads/php/files/37ac37161a41c7913874993bf7499bb8/55857616098.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1607b143671540---mawunanipasonapi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a01d8562ca7---niruxokarifidulepalex.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bd1d56057a---63588862061.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d3a2cb2dd1---dugefizoped.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076a42d6e150---38667450724.pdfIn PDF document text
    • http://araonline.hu/uploads/file/45301771400.pdfIn PDF document text
    • http://inphilong.com/upload/files/21983304744.pdfIn PDF document text
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/83fc8d0f121418e64ff5f2a78e0facf3/gutadov.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160be210acaee2---wakuvamix.pdfIn PDF document text
    • http://icsbc.ru/fuploader//file/39750531868.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/d7o1gp9qagbl5tdv06osmluf06/verevotodu.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c974e012499---8833315275.pdfIn PDF document text
    • http://wrhs1976.com/clients/0/08/080801f2a31a95d446b71e9836a5425d/File/40117665607.pdfIn PDF document text
    • http://tryinvest.eu/userfiles/files/fadapidotexe.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160830495993f1---52110081632.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f64b43b35b---lokinavimaranutosogel.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a60b704f3ca---70464196095.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/84680716592.pdfIn PDF document text
    • http://tuanayapim.com/rsm/files/mujojodudal.pdfIn PDF document text
    • https://okud-istra.hr/userfiles/file/zenobizopefu.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096c00d34691---dofovisefuvu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=tori+and+andre+kissPDF 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_off000162f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x162F2 10152 bytes
SHA-256: caa2134f049bde598504ee6b8d9649fe7727e8fe3bd9fbc1625e0d630bad6f56
font_01_sfnt_off000179c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x179C1 17664 bytes
SHA-256: b38e107a6611f2394235ba1136e7cebea83bd1efb46a0953fdfb41974b0be98e
font_02_sfnt_off0001a814.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A814 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1