Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91dd771f0f383e6…

MALICIOUS

PDF

85.5 KB Created: 2021-06-27 03:54:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c21c7d6b3209815f55e84ac3117c5e7f SHA-1: 5ebb258c47b7ad2feb31c0c20b5f6f357cd5635c SHA-256: c91dd771f0f383e68be97b83bae4f151cc8425f4b1350e7ef60521a4f9ce4675
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites, suggesting a link farm used for phishing or distributing further malware. The presence of external URIs and link farms on disposable hosting further supports this assessment.

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://nomylo.ru/uplcv?utm_term=annals+of+yoga+and+physical+therapy
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2b6b90696---lefanisuvomitugajoti.pdf
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a46913b528e---43337063035.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ade3f6b956e---wewimin.pdf
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/66610fe557ebf0de08dd610c2af33429/tuleduvajebi.pdf
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b182907402b---wepube.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/bab2a70bd461d377b58ab0c0c92bd0a6/60715796185.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/kf1iqcb9lbb6b9oqt04gsj23q5/63363007055.pdf
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/1976c7189715b4ffc43827559615fb4a/95171625952.pdf
    • http://automozg.by/upload/editor/files/53392383045.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/qb1vpedn77c49d4b02so6rj2hq/nidejibidix.pdf
    • https://pjkconstruction.ca/images/file/gopixivovirulugu.pdf
    • https://tavio.ru/files/file/9760819637.pdf
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/vjuveo3964k0hlbdtv3cvh60u5/1768651955.pdf
    • http://baigeleather.com/userfiles/file/lukanigaxamola.pdf
    • http://amon-syotengai.com/userfiles/file/23412584144.pdf
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608eb13758a0c---leladibul.pdf
    • https://manuscripthandler.com/userfiles/file/85077056934.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/qerda6romep1bd4rt12flf8uk5/17577143970.pdf
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/c952a3c0a0aad9e6a6f906e4032253b7/kixogokimodoxidoxapulozu.pdf
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/cafdc30f8f03bc6158c26b0a6e371d3f/dixegexekefodapuzikomo.pdf
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/14de13b5300719c3514fb4bb663b076e/61623898332.pdf
    • https://kodcomputers.ro/2664/uploads/85512762677.pdf
    • http://doellefjelde-mussemarked.dk/images/newsmail/file/93402019055.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_off0000eac9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAC9 16792 bytes
font_01_sfnt_off000102e0.bin
fb51d21f9d2ab760da74ec66601633249ed06a549bf4a54f0b2cb5045ce10f0e
pdf-font-stream PDF embedded font (sfnt) at offset 0x102E0 10992 bytes
font_02_sfnt_off00011c35.bin
4442ea2a3976f06e9383ad06f90cfdd72e3f49a24320c18a0f496db277a2ffd1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C35 17048 bytes