Malicious PDF — malware analysis report

Static analysis result for SHA-256 91b4061f87322681…

MALICIOUS

PDF

77.3 KB Created: 2021-09-22 14:59:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ba5fa6a311451ca7273dd07c1c844576 SHA-1: 866cf8836fdfc3b655906b974f479a190d790694 SHA-256: 91b4061f873226811ff631a06c6324adcad79550079d1d23b70fce636b30d4ec
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal malformed streams and numerous links pointing to compromised websites and disposable hosting, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics strongly suggest the document is designed to redirect users to malicious sites, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://oniceh.ru/uplcv?utm_term=diverticular+disease+diet+pdf PDF link annotation
    • https://inverpalmas.com/aym_image/files/28491621341.pdfIn PDF document text
    • http://privateeducation.sg/verzsape/demo/upload/admin/files/50701251804.pdfIn PDF document text
    • https://bor-diing.com/upload/files/fifafiren.pdfIn PDF document text
    • http://whatcanidoforyou.eu/publish/file/26994135512.pdfIn PDF document text
    • http://vietsonplastic.com/uploads/userfiles/file/88890005668.pdfIn PDF document text
    • http://diskacme.dk/images/upload/file/merat.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16144fb66e3f7c---59600345750.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613d3f8eb0b63---5531621040.pdfIn PDF document text
    • http://eco-building.cz/UserFiles/File/mataxifajonopadetadu.pdfIn PDF document text
    • http://www.primariasantana.ro/uploads/file/38767771768.pdfIn PDF document text
    • http://kxqcgs.net/filespath/files/20210903200030.pdfIn PDF document text
    • http://polesprogettazioni.com/userfiles/files/94399487838.pdfIn PDF document text
    • http://dragonspond.com/uploads/files/mulofafirew.pdfIn PDF document text
    • http://builderall.info/userfiles/file/jajewigimutavo.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/wenusokuveximax.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/161381a827a44b---99813069659.pdfIn PDF document text
    • http://lapalettedesarts.fr/gestion/file/84645835336.pdfIn PDF document text
    • http://budohurtsa.pl/userfiles/file/gezududexurapotisowag.pdfIn PDF document text
    • https://remont-bez-zabot.ru/files/file/narobenamedewolo.pdfIn PDF document text
    • http://culbertsonlawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/47959067572.pdfIn PDF document text
    • http://word.mn/uploads/assets/raxajajazoruxusunigi.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/mukivugesutarowin.pdfIn PDF document text
    • http://tnslib.tools/userfiles/files/romifofibofor.pdfIn PDF document text
    • https://galerieportelouise.be/userfiles/files/63387246673.pdfIn PDF document text
    • https://childprotectionindia.com/lexcyberia/userfiles/files/80895825779.pdfIn PDF document text
    • 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_off0000c9ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9AD 10556 bytes
SHA-256: 5443fdf62f1f8a214ee3427f961cae284cc561a5be7cc86ad5125a672aebdc5a
font_01_sfnt_off0000e1ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1EF 17740 bytes
SHA-256: ea824258d6ee828c143c000fe5f1fa66f5017d41879a56cdfa41cebbca6de79d
font_02_sfnt_off00010f98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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