Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1a18e27e51c2350…

MALICIOUS

PDF

78.5 KB Created: 2021-09-05 14:04:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c72cbcd7301137c44c2014e707d95a62 SHA-1: 6b508cd36cbd05c58bd10ec5dd9c56b0f26b49c0 SHA-256: e1a18e27e51c2350b5ce13a949900bc890564c1d56186e115d7a1ab348d80273
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://alnadaoil.com/userfiles/file/49482990467.pdf In PDF document text
    • https://kurishupally.org/userfiles/file/wizuwosatesarupedu.pdfIn PDF document text
    • http://studiotrusso.it/userfiles/files/gorudexebejigagovokumolel.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/160819b6465aaa---12118133078.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070063a66b79---vuvedavitiseludinuribevar.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/10794848989.pdfIn PDF document text
    • http://toyotaquangninh.org/data/dulieu/files/1904729750.pdfIn PDF document text
    • http://cana.vn/uploads/userfiles/file/vojomixegev.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/437fac6b6ba263216b85b9630fa64088/42563279184.pdfIn PDF document text
    • https://ltgtrends.com/wp-content/plugins/super-forms/uploads/php/files/8ae5b5f64e1deaac27c5480c33b0a37b/xikirujubomowerub.pdfIn PDF document text
    • http://vgkbuilders.com/assets/files/37209077401.pdfIn PDF document text
    • https://www.area-tlc.com/public/ckfinder/userfiles/files/10806860501.pdfIn PDF document text
    • http://slstudio.it/userfiles/files/81568105312.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/lv27ddkjcq4d890dd7l0ufabsd/simemenasuluzowo.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/riribumijufizaxanamozob.pdfIn PDF document text
    • https://freedomhypnosisnyc.com/wp-content/plugins/super-forms/uploads/php/files/953c1bdcffd434a77b7f5345ccd3b03b/mobixuluni.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/70880300277.pdfIn PDF document text
    • https://electroagro.es/pub/files/xapedamajuvufajexevum.pdfIn PDF document text
    • https://najlepsze-w-polsce.pl/uploads/japol.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f5b9c471b63---65123669272.pdfIn PDF document text
    • https://yingzhaoliuart.com/upload/file/wabanakevos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=worksheet+counting+numbers+1-10PDF 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_off0000cfa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFA8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e7bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7BF 11004 bytes
SHA-256: 1a52705fd88ca0150aea8eebf1a5e640f442fc0b6e914b02d1ab94548ae77546
font_02_sfnt_off0001013d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1013D 16900 bytes
SHA-256: 3bed20dbec7e58d02c25d9990da1d952f4182af906b85dd695be1c8ced75d85f