Malicious PDF — malware analysis report

Static analysis result for SHA-256 d272dc6b136d4778…

MALICIOUS

PDF

99.1 KB Created: 2021-09-19 13:18:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1431f0393c9108e1007082e8f56c549c SHA-1: 6dd82d23679ba3e77ce91e606ec3cbe587c02242 SHA-256: d272dc6b136d47782e7f7f8dd8cad88abb0e6fc64627c9be7040a203fe030f2f
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV both strongly indicate this PDF is malicious, classifying it as a phishing trojan. It functions as a link farm, directing users to multiple external URLs, some of which are hosted on compromised CMS upload storage and point to other PDF files. This suggests a multi-stage attack where the initial PDF serves as a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://xn--z4qq44i.tw/upload/actfiles/zonavusuf.pdf In PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/16130495e8511d---58704454283.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/16133aeaec42b2---45886341060.pdfIn PDF document text
    • https://romalasergroup.com/userfiles/files/40988606306.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/luxel.pdfIn PDF document text
    • http://palakkadtourism.in/ckfinder/userfiles/files/26539514296.pdfIn PDF document text
    • http://schoonhovensvrouwenkoor.nl/ckfinder/userfiles/files/wekovojawolabudedib.pdfIn PDF document text
    • http://studioboscono.it/userfiles/files/5169480789.pdfIn PDF document text
    • http://anthonyjcincottalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/86872315779.pdfIn PDF document text
    • https://mimpishio2.com/contents/files/dovagifurufotiwafamilu.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/kanusawexejadasemil.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/161131463434.pdfIn PDF document text
    • http://tjjjsh.com/uploads/files/31336297207.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7eeed0366---kodavefix.pdfIn PDF document text
    • http://eros-arena.name/eros/userfiles/file/9635415713.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/88158172449.pdfIn PDF document text
    • https://sanidom.pl/img/file/titepipexarinovugojotibu.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/wukizugijudoz.pdfIn PDF document text
    • http://najlepsietorty.sk/uploads/fck/file/72992832569.pdfIn PDF document text
    • https://braus.uz/images/shared/file/8471105581.pdfIn PDF document text
    • https://vinaarc.com/app/webroot/files/ckfinder/userfiles/files/vorutanugigipadukutoru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=one+mo+chance+123moviesPDF 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_off00011daa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DAA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000135c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135C1 10688 bytes
SHA-256: 238413d49f1f7de3d77c9839a32b9867ab36c01a0a208e8752ca3966d5bcf47a
font_02_sfnt_off00014e30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14E30 18884 bytes
SHA-256: a8ee35a556106ea344c675c97e5b2e122d52caf9bba6b2ee16d5c7535853c947