Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b20e7a59fe05db3…

MALICIOUS

PDF

86.9 KB Created: 2021-06-26 13:47:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ef94c1863d64cb259cb5be8b99f4f92d SHA-1: d694bbb941ae4cfbe7c001bb16fd5d02c9fc370c SHA-256: 3b20e7a59fe05db3fadde60d90011c510e56e6fd65f6eeef3c09df2e5775ed76
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it's a link farm on compromised or disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, but the presence of numerous external URIs suggests an attempt to redirect users to malicious sites. The SE_CALLBACK_LURE heuristic further suggests a potential phishing or scam pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://archism.ru/uplcv?utm_term=greek+chickpea+fritters
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/ae7841a08ad5dfa78ca0f695f634fc84/wugimaxixevi.pdf
    • http://sushi-belovo.ru/files/lovebixi.pdf
    • https://k-newsletter.com/ckupload/files/ruraz.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/juuv9h7obbm915o591u3ba59ka/jafezoxekavomiridopaki.pdf
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b997c725c94---masotujavurejutejafukaf.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/3d0658f0384763b1ee60feaf7d326c3a/29007054956.pdf
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/29ogltm7nmdto9tbct3i2h3pfs/67933078885.pdf
    • https://mujeresenmovimientoplus.com/userfiles/file/sinaxesaxapud.pdf
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/9d8617572c3cbf8fabc5d251d0721673/41333756050.pdf
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160970efdc2e70---88647219736.pdf
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/9bbba6f4d55fb4d8362b97c3354a6b15/80971731244.pdf
    • https://victorybear-info.com/userfiles/files/45374217776.pdf
    • http://alemotta.com/resources/original/file/22727813972.pdf
    • https://africanresearchcenter.com/userfiles/file/11136380613.pdf
    • http://wmehoa.org/clients/d/df/dff1b85474dadb967ea0c40f6d5e37f8/File/15160448155.pdf
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/2c9ael5unqj0lsvv9lqk2u1pev/21793203589.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/bulojaxejoguduweneb.pdf
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1609b3f8a50cad---90964380307.pdf
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160c207784da7f---jadetanuponigasiz.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/66075314027.pdf
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a04efc58e0d---31381622397.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/934ff09dba846a382373a1322efd617c/xogubu.pdf
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160702f94188ce---tawurivugofake.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee22.bin
abaf19954a6a246718141646f57579971d1dde1dec431e6fd512d3f4b64c6baa
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE22 18444 bytes
font_01_sfnt_off00011e8a.bin
2e9521075b9cede038408ef3354f8054b9a63885a83b3ea308c08c80c238a7c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E8A 10440 bytes
font_02_sfnt_off0001366c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1366C 16792 bytes