Malicious PDF — malware analysis report

Static analysis result for SHA-256 f16ff7c41f35f2c7…

MALICIOUS

PDF

79.7 KB Created: 2021-09-16 10:51:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 101218273c431eb3b6dd4431c0565182 SHA-1: d1a9b9148b3ef2bec8b5edbdc23889b84a82f0dc SHA-256: f16ff7c41f35f2c7b3c76a0cf2888b0c1761a34f9d7bead40b07d9e6d1086cf1
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The presence of multiple compromised CMS upload links suggests a tactic to host malicious files on seemingly legitimate but compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://darangyi.com/userData/board/file/6587557871.pdf In PDF document text
    • http://tao-oita.com/admin/upload_filesfile/62433478108.pdfIn PDF document text
    • https://getadoc.in/ckfinder/userfiles/files/raxejemaworogabaw.pdfIn PDF document text
    • http://nwatchonline.info/userfiles/file/xipukowas.pdfIn PDF document text
    • http://ckattorneys.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dimij.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/161311da74009d---revasanadetedug.pdfIn PDF document text
    • https://krzczonowice.pl/gfx/file/86815184743.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee483825c2---95718534338.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff142ee8f0---renefu.pdfIn PDF document text
    • http://spreewaldatelier.de/img/editor/file/51849417980.pdfIn PDF document text
    • http://fence-alarm.com/userfiles/files/pegor.pdfIn PDF document text
    • http://yibetter.com/data/files/45937504275.pdfIn PDF document text
    • http://aprt1day.ru/file/vajulitomamor.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/lezakoferovawaj.pdfIn PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/8969678543.pdfIn PDF document text
    • https://spcinternational.in/ckfinder/userfiles/files/jajibarejofosuxuvavewezag.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/rigegi.pdfIn PDF document text
    • https://showdetango.com/bafa/userfiles/file/41043671188.pdfIn PDF document text
    • http://kingtonkatsu.com/uploads/files/rolanasoxonipan.pdfIn PDF document text
    • http://tuhocxuatnhapkhau.com/uploads/ckfinder/files/4609427929.pdfIn PDF document text
    • http://radyoislam.com/resimler/files/zurimak.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/10263629775.pdfIn PDF document text
    • http://duoctruongxuan.vn/userfiles/image/file/86293218570.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=information+report+template+pdfPDF 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_off0000d6bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6BF 10440 bytes
SHA-256: b27f7a8751993a242ec00a9c4abaf27299bbbfba181d54ded2722575ad002fd3
font_01_sfnt_off0000ee54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE54 16672 bytes
SHA-256: 0e39fdb299e018a2946509a92e835f0f2ee7ea74f89568a85bc26e73d37c1186
font_02_sfnt_off0001193e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1193E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1