Malicious PDF — malware analysis report

Static analysis result for SHA-256 c661e56f49a43d83…

MALICIOUS

PDF

85.3 KB Created: 2021-09-12 03:57:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: bc961a635d84f55434614b8ba079744b SHA-1: 78380950fe83c2587fe77ccb67c98e96f605dda8 SHA-256: c661e56f49a43d83f8f303d8ac0bb0f344d87a741314d443c0790e34ca97de47
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users. The document body is heavily obfuscated and unreadable, providing no direct content-based clues, but the overall structure and URL analysis strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://combatkuntao.com/ckeditor/ckfinder/userfiles/files/208101512.pdf In PDF document text
    • http://lachina.cn/upload/file/lolopuzajuvulosiv.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613237ec5fa4f---31945145067.pdfIn PDF document text
    • https://fong-cai.com/upload/files/12173108844.pdfIn PDF document text
    • https://episcopiaoradiei.ro/files/degogize.pdfIn PDF document text
    • http://tion.hu/upload/file/xejidazajevipogubifobezid.pdfIn PDF document text
    • http://chamdure.com/DATA/files/58800088955.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/82021217012.pdfIn PDF document text
    • http://jonkmp.nl/img/cms/file/polesutoselalubevapulufik.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202109021518097807.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6ae3b3bd8---3724338227.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/jogededobakofogugog.pdfIn PDF document text
    • http://gibisch.biz/files/files/51325781917.pdfIn PDF document text
    • http://buddhavehicle.com/userfiles/file/74052852355.pdfIn PDF document text
    • http://impactpluslearning.com/ckfinder/userfiles/files/73919635675.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/9bb30eb06da5913f67b8c1523083c679/88638346936.pdfIn PDF document text
    • http://tienphat.vn/imagesflashupload/file/zuxexonijumupovi.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210910042506.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/logogerevofiwajuf.pdfIn PDF document text
    • https://ebal.ro/app/webroot/files/userfiles/files/84173268867.pdfIn PDF document text
    • http://hotelpenza58.ru/ckfinder/userfiles/files/22179390991.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/4ngj76ks5641aclbfkgfma1ii2/78080225162.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/33655211700.pdfIn PDF document text
    • http://shijijiaming.net/filespath/files/20210906175128.pdfIn PDF document text
    • http://emirates-offshore.com/uploads/image/file/27720033633.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/21986051068.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=adjusting+lie+angle+on+wedgesPDF 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_off0000e7e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF5 18308 bytes
SHA-256: 3ff82f0322429051c49713148e506e79ed8e4415c37e4a3cc7d8f84863906ea2
font_02_sfnt_off00012f38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F38 10620 bytes
SHA-256: e6aa0a2ad9c0e9fad9e76b96cdbae7024abfc7c6eaf39f44d9820ed9d62f5363

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