Malicious PDF — malware analysis report

Static analysis result for SHA-256 fcda87c782d1af97…

MALICIOUS

PDF

74.3 KB Created: 2021-09-21 02:15:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c517167104c4b413cf485b52403d98e5 SHA-1: 8dd64092d187b4fae9ab5d7a6d6ed47f4b03e621 SHA-256: fcda87c782d1af97be9c29bf7598e92d8890ab162c4dea4185dd3c4f7671b7a3
126 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous embedded URLs, many pointing to potentially malicious PDF files, and one heuristic specifically flagged it as a link farm on disposable hosting. The document body is heavily obfuscated and unreadable, suggesting it's not intended for direct user interaction but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://mebel-moscow.com/content/xuploadimages/file/woxajasixinetogutuji.pdf In PDF document text
    • http://blccy.com/userfiles/files/toxed.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/somaxopokowefasisiboruf.pdfIn PDF document text
    • http://dcbestwings.com/uploads/files/junugowazawifibe.pdfIn PDF document text
    • http://dharkaninternational.com/survey/userfiles/files/93399564359.pdfIn PDF document text
    • https://livredart.com/ckfinder/userfiles/files/28400079784.pdfIn PDF document text
    • http://i-physiology.ru/upload/maxivox.pdfIn PDF document text
    • http://jungvassar.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/21767394998.pdfIn PDF document text
    • https://gamepinleri.com/calisma2/files/uploads/69748683899.pdfIn PDF document text
    • http://rm-centr.ru/uploads/file/90206527262.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210910222059.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16134437a4eb80---78464894467.pdfIn PDF document text
    • http://csc0311.com/userfiles/file/20210921051255_bgl3a8.pdfIn PDF document text
    • http://yarpb.ru/pic/userfile/64723549569.pdfIn PDF document text
    • https://imihwa.com/uploads/image/20210901/files/20210901211709.pdfIn PDF document text
    • https://websbag.com/uploads/files/4764101907.pdfIn PDF document text
    • http://onlinecommerce.bg/uploads/pages/files/1859536385.pdfIn PDF document text
    • http://ifap.it/images/file/foxowejetixu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328f3a35f15---nevebotobizavuruwes.pdfIn PDF document text
    • http://massiimo.com/piceditor/file/parerovo.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021091203270624.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/42693467585.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109100406236077.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop/contents/nuvoketapisog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=albion+brisbane+postcodePDF 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_off0000bb9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB9E 10628 bytes
SHA-256: d27e86b2ab026928f94874771d85c919f7e775c5e80b95e7671c242f896ee34d
font_01_sfnt_off0000d3d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D0 17576 bytes
SHA-256: 893414f069b2feb8689eea370702071f9ae32e4a5926faf381652bdd607cdfef
font_02_sfnt_off000101f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1