Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a3329c4b48df463…

MALICIOUS

PDF

79.9 KB Created: 2021-09-19 08:09:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 030fa24a5233678b891b2cda47813776 SHA-1: 0d435f09f393172a8beb73b57a8869311f766e3b SHA-256: 9a3329c4b48df4635f921194b930b202ef7a56ff9fe2a36b59c0138408b62c9f
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload directories. The ML classifier and ClamAV both flagged this file as malicious, with ClamAV identifying it as a phishing trojan. The presence of a link farm on disposable hosting and links to compromised WordPress sites suggests an attempt to lure users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://gonguyenkhoi.vn/upload/files/64770088752.pdf In PDF document text
    • http://marikitaberbagi.com/userfiles/file/16110474519.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/uo6jtmgtva6jkf9kn4j1gkn2k2/nejulidurig.pdfIn PDF document text
    • https://duproject.com/uploadEditor/files/79027332460.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/161304370d76dc---27251688303.pdfIn PDF document text
    • https://www.indoorclub-informa.com/boletines/img/file/suredezajib.pdfIn PDF document text
    • http://coral-travel66.ru/admin/ckfinder/userfiles/files/9639799114.pdfIn PDF document text
    • https://braindevelopmentmaps.org/userfiles/files/184564084.pdfIn PDF document text
    • http://scandirent-new.ru/uploads/assets/file/rinurosalonerukami.pdfIn PDF document text
    • http://areaengineeringsrl.eu/userfiles/files/vasidakivexagejutinupigoj.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/50812635465.pdfIn PDF document text
    • https://armature.ir/cache/fck_files/file/38619262735.pdfIn PDF document text
    • https://franciscovalles.comtraining.cl/userfiles/files/gumanozebane.pdfIn PDF document text
    • http://omni-links-europe.com/images/blog/file/19804051438.pdfIn PDF document text
    • https://fptica.ru/images/file/wekotem.pdfIn PDF document text
    • http://sieuthibds.net/images/files/resadutaguma.pdfIn PDF document text
    • https://norservis.com/files/files/79786441056.pdfIn PDF document text
    • https://ambient-interier.cz/files/files/45140697410.pdfIn PDF document text
    • http://citescolairedeledit.com/include/file/gopezedajajunuwanikusoz.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/161363d9a80abe---80866613137.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/16143f7f43bb52---32194304448.pdfIn PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/poleximixalebivixuwa.pdfIn PDF document text
    • https://repairbase.net/FCKeditor/editor/filemanager/connectors/php/images/file/wepowonopatugewe.pdfIn PDF document text
    • http://xmst.com.vn/app/webroot/uploads/files/22862354222.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=smart+app+protector+for+androidPDF 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_off0000d63d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD63D 10640 bytes
SHA-256: 398508f5bee31c5026205ab8caf4a0a0d7eb0a4c1b5d6972794bd66f54324963
font_01_sfnt_off0000ee8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE8B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001069d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1069D 16908 bytes
SHA-256: e1b2e70ab820a1e05dff7de1628ddcf0038e12b0d4cfdb9638ab3f5845793ae6