Malicious PDF — malware analysis report

Static analysis result for SHA-256 33eaca7fcf497f92…

MALICIOUS

PDF

81.7 KB Created: 2021-08-09 14:57:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 41588321d73c2050ee72feb4939dcb43 SHA-1: edcc919a80afbd72b5a46958a313a120943dfb81 SHA-256: 33eaca7fcf497f9235022b622a19356f89dce8a0d9211fd576574c1db6fd2a2d
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs, many of which point to compromised WordPress sites used for hosting malicious files. The 'SE_CALLBACK_LURE' heuristic indicates the document's content is designed to trick users into calling a fraudulent phone number, a hallmark of callback phishing scams. While no scripts were explicitly extracted, the ML classifier and ClamAV detection strongly suggest malicious intent, likely involving the embedded URLs to deliver further payloads or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • 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://infrive.ru/uplcv?utm_term=edexcel+further+maths+books+pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161040fa835aa7---bawamizemopojokezoger.pdf
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/1a5975465396c40bcbe479af83bfe35f/35088319095.pdf
    • https://atlastoursntravels.com/userfiles/file/67045208357.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/qfvs6r2rcjqt6ibuc9q69mj0fi/dotezewapavotunepimolop.pdf
    • https://j-kowalewski.pl/uploads/userfiles/files/82672323499.pdf
    • https://autonoleggioassereto.com/file/rikibo.pdf
    • http://2ds-creations.fr/userfiles/file/17492850745.pdf
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/ab9666221fb44257836e8de64844b8a9/vavijeb.pdf
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/gb98rt7pvl3c19udadkljvlnch/53687056686.pdf
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/86807522220.pdf
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/b9e31ccce0ead7a8e9d2a7226ac6ea56/3193290348.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/ca80a9ea87a9647198082afb9514d999/98418299646.pdf
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/e45405111b72817d38cc58734431f52e/demuvopikoruzi.pdf
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/bf9am820itkhpv8cf1htt9uvd7/bonanupe.pdf
    • http://bmsorganica.com/userfiles/file/79051345229.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/v45cd800ipg6q3kc7tmqoesg91/6179403838.pdf
    • http://nawooelcs.com/upload/userfiles/2021/07/files/210707173253.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1607270ce2e594---negolukuvifogiveda.pdf
    • http://landpas.pl/upload/file/74087092409.pdf
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b88b3c8e0fc7614e46579b0b06d65d63/lasujane.pdf
    • https://rtvpuls.com/ckfinder/userfiles/files/bukusegavulafezefofogiru.pdf
    • http://ahchala.com/img/file/dativokedaxotepujuj.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c3bf.bin
adf38969d40f501586e0caf93d33991e243baeeecfe575c4831cdbf64b7044fa
pdf-font-stream PDF embedded font (sfnt) at offset 0xC3BF 16336 bytes
font_01_sfnt_off0000d9bd.bin
a0706c355664579afd0b81d4d689e5001f4c5f832c744f0e3f6be62f7a6ba075
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9BD 16860 bytes
font_02_sfnt_off000105ed.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x105ED 16792 bytes
font_03_sfnt_off00011e04.bin
1a2dcbd1e783f7067a0a4219e96d9525667b6d40362f6f977b8ecb5e443d4550
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E04 11108 bytes