Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d4853602895318…

MALICIOUS

PDF

70.0 KB Created: 2021-09-27 07:12:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: aa330a8b611c7e0c1fdfb48f4f692cdb SHA-1: b4613895c5edf5fed6741187f901a85039294df9 SHA-256: 81d4853602895318fa8e80c5a979f9f6f3cc4f3148f6e34600a5dabb93aa456e
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. The document contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute malicious files. The presence of multiple unknown URLs further supports the phishing and malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b51c55cdde---zowajogobane.pdf In PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/zagupudupiviso.pdfIn PDF document text
    • http://cn-biyoute.com/d/files/10556568351.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1614fb5b52be75---35562869104.pdfIn PDF document text
    • http://w.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/natesibeviriru.pdfIn PDF document text
    • https://777mto.info/contents/files/kanuvetet.pdfIn PDF document text
    • https://ljlconst.com/admin/images/file/16059561538.pdfIn PDF document text
    • http://centrons.com/uploaded/file/1858259467613d941b20b5b.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/161498b3c03b40---50628239153.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/zofapekisew.pdfIn PDF document text
    • http://hardiebase.com/uploads/assets/filefile/48856795992.pdfIn PDF document text
    • http://lisaarkin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/konusulokode.pdfIn PDF document text
    • http://sov.tranovice.cz/webpagebuilder/ckfinder/userfiles/files/kafupolegutumunapefilagi.pdfIn PDF document text
    • http://sgrdpandher.com/userfiles/file/23231272553.pdfIn PDF document text
    • http://gzafjc.com/uploadfile/files/24275467251.pdfIn PDF document text
    • https://www.sibirprokat.ru/ckfinder/userfiles/files/fujasof.pdfIn PDF document text
    • http://zs-oilfieldequip.ru/d/files/2891823838.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16150b8a54169a---16647560877.pdfIn PDF document text
    • https://finliz.lt/i/File/bibelumedomu.pdfIn PDF document text
    • http://bjqyms.com/filespath/files/20210902111745.pdfIn PDF document text
    • http://dison.cn/filespath/files/20210913121627.pdfIn PDF document text
    • http://loadcell.vn/Images_upload/files/38666497631.pdfIn PDF document text
    • http://thetestmag.com/userfiles/files/39197246921.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=download+play+tube+apkPDF 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_off0000b181.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB181 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c998.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC998 10560 bytes
SHA-256: b55b8860c1a500a42981b23f2f60ea549cc26c24ff24ec64f1af89b9074db43c
font_02_sfnt_off0000e19e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE19E 16092 bytes
SHA-256: e787df552409168bcfee92e9ab39d5d73125e8d6cc47007642eb0a0ee4493a29