Malicious PDF — malware analysis report

Static analysis result for SHA-256 def1aaeb3a9b1897…

MALICIOUS

PDF

79.3 KB Created: 2021-09-16 06:29:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 10ad2f6f0f4bcd0ffc771313d62f9e96 SHA-1: ac88ee7704f2320e5aed1edf2460fa6c7fe63a4c SHA-256: def1aaeb3a9b18979e431aca4aa5699ec9d68b50714f947cb4113c6ac8137d7c
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis confirm the malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://remini.hu/userfiles/file/xutenemobivedapin.pdf In PDF document text
    • https://drbumbnursinghome.in/ckfinder/userfiles/files/dipowezaserujiviguduwu.pdfIn PDF document text
    • https://tinhhoaxanh.vn/userfiles/file/32983540904.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/b8fr50iedevshamdn2d95v7872/natora.pdfIn PDF document text
    • http://iehyun.com/editorupload/file/fakerugiwinimitujelodu.pdfIn PDF document text
    • http://mauchlineware.com/html/chapelstreet/web/userfiles/files/47357064711.pdfIn PDF document text
    • http://bumsnab.ru/uploads/files/filakuboramowezolaf.pdfIn PDF document text
    • http://avesta-hmora.boj.se/uploads/userfiles/files/zuxevobajoravubagerulox.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b209259016---83805945691.pdfIn PDF document text
    • http://vigova.vn/Images_upload/files/mizogevoporizifo.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/2021951947158215.pdfIn PDF document text
    • http://tz5168.com/uploadfile/image/2021/09/08/file/20210908_032706_120.pdfIn PDF document text
    • http://musicincw.com/fckeditor/userfiles/image/radij.pdfIn PDF document text
    • https://rainbowfurnitures.com/files/files/37469572618.pdfIn PDF document text
    • http://karmakonnect.org/DrumiBhatt/karmakonnect.org/Final/ckeditorimage/files/39750178124.pdfIn PDF document text
    • http://kasaitogo.com/uploads/files/texisorevurarugulanad.pdfIn PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/65613545901.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/67d311458db9a230e093dec14ef29a6d/pazulel.pdfIn PDF document text
    • https://delphin-bau.com/ckfinder/upload/files/guwuxugefugobinu.pdfIn PDF document text
    • http://pune-india.info/userfiles/file/25872940943.pdfIn PDF document text
    • http://heatherjansch.com/ckfinder/userfiles/files/13439638251.pdfIn PDF document text
    • https://netshopnepal.com/userfiles/file/moloragipidovagewesifoju.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=rgb+to+hex+c%23PDF 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_off0000d06c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD06C 18592 bytes
SHA-256: 613932070032779346628b5c7298e1518e069fe15e90a9123c99564e7ca6815c
font_01_sfnt_off00010144.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10144 10124 bytes
SHA-256: b3b6a1d9ea9e2c5ce46a2c226b1b72912d30573541590f655612378207b01598
font_02_sfnt_off0001180f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1180F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1