Malicious PDF — malware analysis report

Static analysis result for SHA-256 c090d0c534535499…

MALICIOUS

PDF

79.6 KB Created: 2021-09-16 21:38:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 543c1c71bd33b3ec30390217d7365ea9 SHA-1: 9eefce94f6bdc52142dde3f3c68a045d07d8e5f2 SHA-256: c090d0c534535499f392ccc1d517794e1647dfe7d6113cc9d13ed88243bf0b02
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or are part of a link farm hosted on disposable domains, indicating an attempt to obscure the final malicious destination. The presence of these link farms and the ML/ClamAV detections strongly suggest a phishing or credential harvesting campaign.

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 http://mmbc.cz/_data/user_files/file/83884711518.pdf In PDF document text
    • http://xingyeknitting.com/userfiles/files/vatamiwif.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/bodapupatunadigatobuke.pdfIn PDF document text
    • https://stop-remont.ru/ckfinder/userfiles/files/39272471939.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/8849579627.pdfIn PDF document text
    • http://www.ap-arte.ro/fckupload/file/xokumuguxukabugit.pdfIn PDF document text
    • https://ist-lb1.istanajp.com/contents/files/lamazudakana.pdfIn PDF document text
    • http://www.cda.org.hk/ckfinder/userfiles/files/papigujoka.pdfIn PDF document text
    • http://ip-malkov.ru/uploads/files/56748943992.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/jevakopasetej.pdfIn PDF document text
    • https://ev-owners.jp/userfiles/files/walor.pdfIn PDF document text
    • http://nordicwalkingturak.hu/_user/file/28646623275.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/0a585d0ad00fa98c2df486c0ab005fcd/21473958271.pdfIn PDF document text
    • https://ladachess.ru/userfiles/file/fexolokokamajazezuti.pdfIn PDF document text
    • http://enslev-anlaegsservice.dk/userfiles/file/xupireralenuk.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/16140747a3be6c---76631101768.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/bonapimokimagiv.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/nomafimefoxap.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/d17004c4e2f025af4af42c0d99531be2/83732725108.pdfIn PDF document text
    • http://goforthegreengolfpools.com/userfiles/file/45085221385.pdfIn PDF document text
    • http://myucpb.net/userfiles/file/1436774100.pdfIn PDF document text
    • https://mamadona.ru/ckfinder/userfiles/files/37534141566.pdfIn PDF document text
    • https://shevian.com/images/file/pipizikekaxuduves.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=creative+pattern+lockPDF 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_off0000d519.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD519 10388 bytes
SHA-256: d1088c20ed13d4f7a49b76d60fb750a921aa634b9a6b09269bb997581ca6fef1
font_01_sfnt_off0000ecbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECBD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104CF 17068 bytes
SHA-256: c276fc64d2a8a2a5187d939fa35f55301f2c9cdf76e0d3008ed0f9e9531b828c