Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a33847516b90df0…

MALICIOUS

PDF

73.4 KB Created: 2021-05-27 21:34:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9b9979299fe6c0c1515ca2dca9506186 SHA-1: d5a41e1b22216c921f2ce9e52d1b8b87d61fb940 SHA-256: 1a33847516b90df04c5cefd43a13b6ff55a59a430043cea6070c2d8b874ec6a3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many of which appear to be hosted on compromised WordPress installations, suggesting a link farm used for phishing or malware distribution. The document body, though heavily obfuscated, contains references to 'sentence completion worksheets 5th grade' and application metadata, indicating a lure to disguise its malicious intent. No scripts were extracted, but the extensive use of external links points to a downloader or phishing attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=sentence+completion+worksheets+5th+grade
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160af66c740118---5218342825.pdf
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d931ad674f---pavana.pdf
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f7c0e44fbe---jijekufewoba.pdf
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16094ca54b00cf---sulijotabowemukedubazez.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3e6d8d9b9---xekikuzetajovire.pdf
    • http://mikailang.net/userfiles/file/20210507111046_1932437367.pdf
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/628678d9fa4ba7da42c1cb481f2f5a2a/40550099935.pdf
    • http://hutergroup.de/userfiles/file/welapoluvejoter.pdf
    • http://stalmont.eu/userfiles/file/75907322566.pdf
    • https://mobilieroccasion.fr/uploads/file/43065495517.pdf
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/704kaoivj5a8fem9jqi35lg8gu/281156178.pdf
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/0fdfa56e27011ea1b263c25ae91b0186/24893416002.pdf
    • https://novahealthclinic.ca/userfiles/file/pigopenuxelovadaro.pdf
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607804344ed3f---90627072469.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c309db7f0b---55687336150.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dfbc.bin
52df5853e1cd6a75c90f6d3df639733f45de704cb2a360dcc17165e303cc7ef8		 pdf-font-stream PDF embedded font (sfnt) at offset 0xDFBC 5868 bytes
font_01_sfnt_off0000f3a1.bin
b3eaef31e71057f65d321e5d4aeb264dbd7c97e7733da869ffd0578fe5dc5f5d		 pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A1 11036 bytes

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