Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4acb31172ac164d…

MALICIOUS

PDF

83.4 KB Created: 2021-09-13 01:52:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 03a5ffcac4022037882aba206c8b3c1f SHA-1: 559fe679820bcffa8a7c7d8cebda8f53afd2ab75 SHA-256: a4acb31172ac164d0ea839e4bc67baed6df501e112f9097044051b20a65a9f38
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external links, many pointing to compromised WordPress sites or disposable hosting, indicative of a link farm used for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://vietsonplastic.com/uploads/userfiles/file/30703066439.pdf In PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/tibapitunudelawoxolirev.pdfIn PDF document text
    • https://viktorina.ledoritulys.lt/files/21336599458.pdfIn PDF document text
    • https://nutstudio.it/userfiles/file/fexetajuwozibatu.pdfIn PDF document text
    • http://artetendasud.it/userfiles/files/lilolexun.pdfIn PDF document text
    • https://warungmimpishio.com/contents/files/38010182134.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133d6bf91580---47103643450.pdfIn PDF document text
    • https://thuanxuongmonmb.com/admin/webroot/upload/image/files/pubej.pdfIn PDF document text
    • https://gegeny.hu/uploads/file/77188226612.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f93aa8567c---batatigelo.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/76514064702.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613673e594dce---pelimazurivikej.pdfIn PDF document text
    • https://hmanagement.net/userfiles/file/pesizijuxexutuw.pdfIn PDF document text
    • http://100gastro.cz/soubory/files/vepikakasokitom.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba79d6b301.pdfIn PDF document text
    • https://soalmatematik.com/userfiles/file/disirofowoxuwusunonez.pdfIn PDF document text
    • https://smgbid.com/ckfinder_userfiles/files/rituketigenuguduno.pdfIn PDF document text
    • http://aedjtjdshbf.pretty-match.com/upload/files/fifopusamuxupukarozuje.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/xofoke.pdfIn PDF document text
    • http://screen.by/images/file/13795596434.pdfIn PDF document text
    • http://xn--b1agaa2anfqdp.xn--p1ai/ckfinder/userfiles/files/vazurupolotane.pdfIn PDF document text
    • https://taxfirma.com/userfiles/file/32747728244.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/98753399150.pdfIn PDF document text
    • http://diakmelo.hu/ckfinder/userfiles/files/21226031059.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/23875861616.pdfIn PDF document text
    • http://xn----8sbemnkjd7bfu.xn--p1ai/design/img/upload/file/84165442856.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=which+app+is+best+for+video+editing+without+watermarkPDF 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_off0000e098.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE098 17008 bytes
SHA-256: 88244df370d15878500f18d0a93a8bdc3c6ca4f07add29d827401ea5df2606f4
font_01_sfnt_off00010c50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C50 11496 bytes
SHA-256: 8a739372e85370ea71734ef29ae35a725887416437caa3c043ba12df6603a8bc
font_02_sfnt_off00012703.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12703 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1