Malicious PDF — malware analysis report

Static analysis result for SHA-256 c16fc7b4d57da1df…

MALICIOUS

PDF

76.0 KB Created: 2021-10-02 09:11:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 52766d8a3a3139899c0fadeef8b929b0 SHA-1: f72676c0f5ec61adfde6d4c903ff15fa94d8b397 SHA-256: c16fc7b4d57da1df6211b1eb463c025d7eedb93bc2e788c67e0dd025aad05e51
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the nature of the document as a collection of links on potentially untrustworthy hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9885

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://laborke.ru/uplcv?utm_term=what+are+the+odds+of+getting+pregnant+from+pre+cum PDF link annotation
    • http://pileki.com/imgup/file/94623542281.pdfIn PDF document text
    • http://rencontres-icare.org/userfiles/file/68483753330.pdfIn PDF document text
    • http://pantryscan.com/123cars/imagefck/file/gewolotup.pdfIn PDF document text
    • https://www.utn.ac.cr/sites/default/files/files/69044822427.pdfIn PDF document text
    • http://proxima-design.cz/files/file/38618586796.pdfIn PDF document text
    • http://automozg.by/upload/editor/files/67182404202.pdfIn PDF document text
    • http://haliburtonhighlandsheritage.ca/userfiles/file/26056803825.pdfIn PDF document text
    • https://estoniapools.com/contents/files/zewikododitafomozir.pdfIn PDF document text
    • http://torby.kbo.pl/ckfinder/userfiles/files/55199495916.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16157ba849d721---papivitamabimaterotez.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cfe355872f---sopodode.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/161498e055aeec---favezi.pdfIn PDF document text
    • https://sibiucuratenie.ro/fckeditor/userfiles/file/vuwiko.pdfIn PDF document text
    • http://mamnonhieutrung.edu.vn/ckfinder/userfiles/files/rofekifaboba.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/73824991370.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c6a9e1f00f---tijixasa.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/76822525844.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/e1e5e757a822516f97ad547a30882f86/lixufu.pdfIn PDF document text
    • http://forti.in/userfiles/file/5544995396.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614a3ff369be6---bokotivogafikebuwesej.pdfIn PDF document text
    • http://hzbmsj.com/images/upload/File/57404718631.pdfIn PDF document text
    • https://interno-kazan.ru/upload/files/javevivefadirobifutuwarex.pdfIn PDF document text
    • http://tele-klass.ru/i/upload/files/49137031322.pdfIn PDF document text
    • https://ngenadmin2.nextgenphotosolutions-beta.com/app/webroot/files/file/95795765985.pdfIn PDF document text
    • http://shinhwacar.com/userData/board/file/9490846082.pdfIn PDF document text
    • http://xn--80aejmo0alc.xn--p1ai/ckfinder/userfiles/files/xozafazotu.pdfIn PDF document text
    • http://www.rupankar.com/fckimages/file/tisidotibuj.pdfIn PDF document text
    • 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_off0000bd8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD8F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d5a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A6 11112 bytes
SHA-256: b7b92d39926499b8da1e283c14e33e9d17f4408a4a99b25aa26a34a3328c940b
font_02_sfnt_off0000ef40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF40 18896 bytes
SHA-256: 45ad5b289ced29170cf6a407c1265c9c3f5b824fe041091eccac49fb0f8c2409