Malicious PDF — malware analysis report

Static analysis result for SHA-256 3725f804b691a10e…

MALICIOUS

PDF

77.4 KB Created: 2021-10-07 18:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 128b6de86dc28d189a82a38dbdd17c08 SHA-1: abe9b35454acc1767dc94c55b833c70e6c2c6fd0 SHA-256: 3725f804b691a10e93a2989a5fc8e150bb504ea8cb75b722a037d020b8ced8fe
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates this purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://medvor.ru/uplcv?utm_term=education+technology+in+physical+education+pdf PDF link annotation
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/sitofedilejazanapi.pdfIn PDF document text
    • https://abhimaninteriors.com/ckfinder/userfiles/files/36859430490.pdfIn PDF document text
    • http://studiogiovannone.com/userfiles/files/bifogawoxiduzeziwakuxi.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4bcd5097fb5fbee5b9fc59793dd33be2/jafapatu.pdfIn PDF document text
    • https://aarushimukhwas.idealviews.com/userfiles/files/3700205653.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/16137fecc82941---jobitefufegebagupur.pdfIn PDF document text
    • http://hunicorn.hu/userfiles/file/69121746076.pdfIn PDF document text
    • http://www.ez4parcel.net/upfile/files/2021/09/07/38768768856.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/pimisewepivuvelo.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/tefubapunulogavunonorax.pdfIn PDF document text
    • https://adrfarysz.pl/userfiles/file/48045129914.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/15792772150.pdfIn PDF document text
    • https://penmypoem.com/new/admin/uploadfiles/file/jejanivuturojidopebobugo.pdfIn PDF document text
    • https://ip-kamera-rendszer.nuttydog.hu/ckfinder/userfiles/files/lufonagokobig.pdfIn PDF document text
    • https://h016s5or78-du3.com/contents/files/49040131890.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/76134892905.pdfIn PDF document text
    • http://cjmfgx.morefriendship.com/upload/files/sadavizipiwexijolidarudu.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615053c624754---48346041045.pdfIn PDF document text
    • http://thebankcardservice.com/uploads/files/zibajuvosezavew.pdfIn PDF document text
    • http://shouce-image.kuchuancdn.com/Public/resource/files/65711964220.pdfIn PDF document text
    • https://xtremefitksa.com/ckfinder/userfiles/files/pudiruwuzajewije.pdfIn PDF document text
    • http://elementsgogreen.com/userfiles/file/13359092202.pdfIn PDF document text
    • http://agilesolutions.in/uploads/nadirexesekopekagepo.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/jetubikufed.pdfIn PDF document text
    • 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_off0000c871.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC871 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e083.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE083 17860 bytes
SHA-256: cea090802587a4d519b3b2bdc938347b9d8518859944fe4228b4c12054cddf93
font_02_sfnt_off00010e5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5B 10996 bytes
SHA-256: 945077c0f60f488438ff3aecd23178530f81e1c8d6b2b3e20c71794e1488ac3f