Malicious PDF — malware analysis report

Static analysis result for SHA-256 f2efbb5c49d8801d…

MALICIOUS

PDF

79.4 KB Created: 2021-09-17 00:17:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 635f7938f261a43ad803ab7d383a266e SHA-1: 38487e817d180f1412f345cffffb89f9a148ee93 SHA-256: f2efbb5c49d8801dadd2d846a5dd9d979dfb7b4b4b382db5577d7181a07d62e9
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm hosted on compromised or disposable domains. The embedded URLs, such as 'https://coretry.ru/uplcv?utm_term=android+1+kick+the+buddy', likely lead to phishing pages or further malware downloads. The PDF structure and the nature of the URLs suggest an attempt to exploit users through deceptive content.

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 https://coretry.ru/uplcv?utm_term=android+1+kick+the+buddy PDF link annotation
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/161348d9719caf---lazonimujexu.pdfIn PDF document text
    • https://maximatrimony.com/ckfinder/userfiles/files/60459795682.pdfIn PDF document text
    • https://www.disbel.es/ckfinder/userfiles/files/kimakerovusesogib.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/10339463758.pdfIn PDF document text
    • https://beautyyaurient.com/editor_upload/file/16781117273.pdfIn PDF document text
    • http://hulstcustoms.ru/uploads/files/jikemojisabopimojuzenija.pdfIn PDF document text
    • https://suacuachuyennghiep.com/uploads/files/runotevuwa.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/0c6ddb2acb3f338bb065d37c585b952f/42955313532.pdfIn PDF document text
    • https://wupaojichangjia.com/d/files/kugozogesajibodora.pdfIn PDF document text
    • http://unibeauty.com.br/ckfinder/userfiles/files/dopusoworenoxikalunegegin.pdfIn PDF document text
    • http://www.kowel.com/ckfinder/userfiles/files/1630518454.pdfIn PDF document text
    • http://location-venise.com/italie_documents/files/guxekofisakuzowenare.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/xudededepepazogepuv.pdfIn PDF document text
    • https://rachelrom.com/rescontent/file/23812485867.pdfIn PDF document text
    • https://hongdung.vn/ckeditor/images/files/70739005988.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/87447149126.pdfIn PDF document text
    • http://studiosantese.eu/userfiles/files/bikagemaramur.pdfIn PDF document text
    • https://angem.fr/userfiles/file/girizejotuf.pdfIn PDF document text
    • https://aimhc.com/userfiles/file/15289560115.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359d47bcc3c---72672374565.pdfIn PDF document text
    • http://congseng.com/uploadfile/files/6389727518.pdfIn PDF document text
    • https://thokhoavietnam.com/upload/files/juvomiwagif.pdfIn PDF document text
    • http://seattledesis.com/fckeditor/file/peluvemi.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_off0000d399.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD399 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ebb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB0 10568 bytes
SHA-256: 138af4e625c9bcbbb3b09cfd5d10af89030e9464097e40b59543f1e38589e71f
font_02_sfnt_off000103c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103C7 17376 bytes
SHA-256: 65570622aef0050f4e68f89f559fa8829d55ebda71fa4975c0ab75c774c76c8d