Malicious PDF — malware analysis report

Static analysis result for SHA-256 ffc5525b68cbeb28…

MALICIOUS

PDF

73.1 KB Created: 2021-09-05 00:01:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 61ccaae4e836b04a4a218628ad3a7643 SHA-1: 5dc9c1eeae693cf6acebafaa1aa24d6a50901521 SHA-256: ffc5525b68cbeb28ed861a5c0b57758a26db7b41cceed393a6736608897a78ee
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to files hosted on compromised CMS uploads or disposable hosting. The ML classifier strongly indicated maliciousness. The document body is heavily obfuscated and appears to be non-readable content, suggesting its primary purpose is not informational but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • 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://yingzhaoliuart.com/upload/file/90812299645.pdf In PDF document text
    • http://pcccmiennam.com/media/ftp/file/zabepejedokomuxurelep.pdfIn PDF document text
    • https://kga-am-adlergestell-ev.de/kga/ckfinder/userfiles/files/15841279565.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/lokomaxezug.pdfIn PDF document text
    • https://tripleccompanies.com/wp-content/plugins/super-forms/uploads/php/files/0e3f175a1e472b6d60a9e6ae662959e6/98374429701.pdfIn PDF document text
    • https://pypconsultores.mx/userfiles/file/63401762836.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/vokupivabojomasuradodolil.pdfIn PDF document text
    • https://www.iieng.org/editor/ckfinder/userfiles/files/83196950439.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610d4c1708537---solerutozowogomab.pdfIn PDF document text
    • https://haidangpc.com/contents/files/pusokilonom.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/3ef66ef755f6c12f417915a97c3c755c/zaletopuzizevujekape.pdfIn PDF document text
    • http://iwilldoit.ru/uploads/files/files/66489886699.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609acc3b5e61f---52194908379.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/87330ca28a655f47e17696217213718b/padewujeve.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607570b0bd928---82107949564.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/669279390dd25fc4dc079b383f222ba1/87054012323.pdfIn PDF document text
    • http://studioagm.it/userfiles/files/furipetaxelomadikagi.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/16112572cb31fe---84230722742.pdfIn PDF document text
    • http://lyzph.com/userfiles/file/Fl202107210952143497.pdfIn PDF document text
    • https://boyanbolyarski.com/userfiles/file/13815738736.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=telugu+handwriting+worksheets+pdfPDF 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_off0000ba56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA56 11020 bytes
SHA-256: 7ab0e60fd75c4babda3048d73658f6927c0a23083bd75dbe1af6945ef4313a6b
font_01_sfnt_off0000d3c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ebd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBD7 16688 bytes
SHA-256: 5bf1d75131d53240f232760db2b793dbdc35cbd492d070e74ef46299efee56cd