Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bd998ba32b0f3b2…

MALICIOUS

PDF

73.4 KB Created: 2021-09-18 07:06:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ffe64cf56226e2f40b237e4a22e0bae5 SHA-1: 6ada97659a1c4922238ddcb1fc0365234bee2fd1 SHA-256: 4bd998ba32b0f3b2423fe71449ea1322b9249e518e837e0e32a37b592a605c15
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the PDF structure itself is used to host a collection of potentially malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • 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 http://www.giuseppe.ru/ckfinder/userfiles/files/65809339034.pdf In PDF document text
    • http://wo-kop.pl/userfiles/file/kifuzovobene.pdfIn PDF document text
    • https://vinatech.com/userfiles/file/kikovupabukibulaja.pdfIn PDF document text
    • https://makanbanyak.net/contents/files/jebinu.pdfIn PDF document text
    • http://kalkulacka-hypo.cz/userfiles/files/fufukevevom.pdfIn PDF document text
    • http://td-mg.ru/uploads/files/minobefadexenotowun.pdfIn PDF document text
    • https://zlato-invest.cz/upload/files/86960614556.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/16132e30437667---53158008967.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/72a905a3d8e224f7e2e1aee866352bf2/fukana.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/38837169398.pdfIn PDF document text
    • https://nexapos.com/upload/files/mugusod.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/vmau453r0sal2qug65hrj5nsl3/fuzavirejogesojazerix.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/chgbr7h18fanoasbf4j5t85rvc/zelivuwawowexup.pdfIn PDF document text
    • https://www.domaine-de-la-ferme.fr/ckfinder/userfiles/files/36322489059.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/cde52b86e7b7288c8d10d271bee6c1d0/jesunonovusasazuradelus.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021091117203642.pdfIn PDF document text
    • https://noventa.cz/media/files/file/78427467113.pdfIn PDF document text
    • https://castel.ro/userfiles/file/89770621091.pdfIn PDF document text
    • http://taiwanquinoafamily.com/shopadmin/upload/files/vibebo.pdfIn PDF document text
    • http://optikametuje.cz/userfiles/file/39813222597.pdfIn PDF document text
    • https://www.gullyracing.it/admin/ckfinder/userfiles/files/gatepim.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1614252b709550---97369604315.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/87896508691.pdfIn PDF document text
    • https://nic-irq.com/userfiles/files/70940028318.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=gangstar+vegas+mod+apk+latestPDF 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_off0000b91c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB91C 10840 bytes
SHA-256: 8805781b8d209385bd5ddb47c3d1fd4a08a0b5c790a4f1519734c2f22312270e
font_01_sfnt_off0000d1fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1FE 17992 bytes
SHA-256: 4c8d9e0b59d2adc8608ecc6a445109757883d8a0e3cf1f9ac882d37b9ba21215
font_02_sfnt_off00010039.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10039 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1