Malicious PDF — malware analysis report

Static analysis result for SHA-256 c38f3fbdf20cd800…

MALICIOUS

PDF

80.4 KB Created: 2021-09-18 07:21:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 88e4f5fbbcc2fd9f9d84e8e9254097ea SHA-1: 2259618ce905c6fc69e4e6d728c095a05a5418aa SHA-256: c38f3fbdf20cd800127c207c5cf5018665d57d62b65a727217cec3c5332ab057
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing users to multiple external URLs, many of which are hosted on compromised websites or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of numerous links to potentially malicious content suggests a broad-based attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://zkmeiqi.com/admin/ckfinder/upfile/files/vujapezalegenimanor.pdf In PDF document text
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/15358150446.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/j1c02b731ndjmfquo95deu562c/85597440073.pdfIn PDF document text
    • http://braindevelopmentmaps-org.neurondevelopment.org/userfiles/files/84526280950.pdfIn PDF document text
    • http://na3.it/misc/file/sokejisugifikojelubenubuw.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/21053546110.pdfIn PDF document text
    • http://se-ty.com/uploads/userfiles/file/lubaxofimi.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/91e2323cdc9a11f391c7dc46e13d0c11/gawowasizipejimedijo.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/tmp/sises.pdfIn PDF document text
    • https://vanphongphampmc.com/upload/files/wowuxunajuzufimok.pdfIn PDF document text
    • https://woodfur.in/userfiles/file/zubaxuvun.pdfIn PDF document text
    • http://isotope3.pm-ural.com/uploads/files/52662853496.pdfIn PDF document text
    • https://ladulceseguros.ar/noticias/fckeditor/file/43596235944.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/pezixudeg.pdfIn PDF document text
    • http://graylegalservices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zejukusototowepakozeru.pdfIn PDF document text
    • http://polaryachts.com/res/wysiwyg/file/zovapofurexirob.pdfIn PDF document text
    • http://abwmercury.com/uploads/files/rawofuwiwomojeb.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161336efe3c5d9---podapovukuru.pdfIn PDF document text
    • http://087334211.kad.tw/kads/ckfinder/userfiles/files/47986113494.pdfIn PDF document text
    • http://limeitec.com/upfiles/editor/files/1970136246.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/161398042edd6c---55426020791.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210915184523.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/piretosakozi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+see+my+phone+ramPDF 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_off0000d65a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD65A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE71 10568 bytes
SHA-256: a8f91ecb9dc0b62c7edaaeb49c960a0719e6f9491965606f295a18edce0fc8a1
font_02_sfnt_off00010669.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10669 18092 bytes
SHA-256: 659f4e7fbfa573172e6cb08dd961b1adedff39ba57c8d3f2fcb980427a50c88b