Malicious PDF — malware analysis report

Static analysis result for SHA-256 03181e54c7c6b4a8…

MALICIOUS

PDF

89.8 KB Created: 2021-07-06 15:07:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: b642a8aa2cf84ea4868c1636904810e1 SHA-1: 19181a33f8eef5fc25f65d111d3268523cdbb96b SHA-256: 03181e54c7c6b4a892c1cea0dda56293e0750798882399c6bd9b57572b2793e3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links pointing to compromised WordPress sites and disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for SEO spam or to distribute further malware. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristic firings clearly indicate the malicious nature of the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16077d50d9e1d1---75172010904.pdf In PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c755144b3f---94037263361.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/gp0dl1hf0plb59lmputourjnok/fadijuto.pdfIn PDF document text
    • http://xn--49s538bo8ux8c.net/userfiles/file/lepijiki.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160992277b23ad---kalakugexud.pdfIn PDF document text
    • http://thy-environment.com/userfiles/files/10147945986.pdfIn PDF document text
    • http://jirehenl.com/userfiles/file/290145258726.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/f965fa25ad207395ed71d4a0eea70929/xoraberibod.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/3b25af5877b71db0a7d20b56296c83d1/rotububagowarejo.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/8dca65a134e2ddeea8f4596803bc951f/lovafenab.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/8em4ghonc5q5b49il1q4a8j443/78159094411.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/0pimka2g8ft1efltgp3rbfe70n/67712751761.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16090e60a48595---nidigufilovavexugivete.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/62888b4015e90468195368e33616f049/tegekezidigojo.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608073d13a342---dusowumivitobokanobates.pdfIn PDF document text
    • http://targhevaticane.it/userfiles/files/metinoxafisadebu.pdfIn PDF document text
    • https://diaochue.vn/userfiles/file/berekuluvafa.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160b7f763e6c2f---30702685398.pdfIn PDF document text
    • https://www.wflorlando.com/wp-content/plugins/super-forms/uploads/php/files/f4dc1bdb33ec50105b12a679dcd8ea2f/18369165150.pdfIn PDF document text
    • http://thesnowmanicecream.com/ckfinder/userfiles/files/punazag.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/35632808601.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e18c44020b---64377505417.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=video+maker+of+photos+with+music+%26+video+editor+pro+apk+downloadPDF 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_off0000fa56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA56 17704 bytes
SHA-256: fc73073073c8fd987170f5e4eb02189bb6e98949da4033d72e369aba8a16f1b5
font_01_sfnt_off0001280a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1280A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014021.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14021 10980 bytes
SHA-256: 54758cd0baaa87b9111aab97102ab2512ff95ab1a13bfecb21014df44d3fcf55