Malicious PDF — malware analysis report

Static analysis result for SHA-256 1ed8f1d93af1c6aa…

MALICIOUS

PDF

71.8 KB Created: 2021-10-04 00:18:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: f4cd912f8f233a7f6614d9665e675c54 SHA-1: d05fb0d80d00bb2392594d6f918febf85914b2d4 SHA-256: 1ed8f1d93af1c6aa4c34d9f7c5a66df868c8f6a4d935d6e2587092b9cebaf645
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous external URIs and links to compromised WordPress sites, indicating it functions as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests these links are on disposable hosting, commonly used to obscure malicious activity. The primary purpose appears to be directing users to potentially harmful content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://catamma.ru/uplcv?utm_term=group+of+non+flowering+plants PDF link annotation
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614b76d429cfd---54300044437.pdfIn PDF document text
    • http://aweibel.com/Photo/file/82585740356.pdfIn PDF document text
    • http://dagmar-e.de/userfiles/file/bipetumofazujirax.pdfIn PDF document text
    • http://abcbyspu.net/ckfinder/images_store/files/2487558055.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614a2d7b8ef88---ravosotitet.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/12415325011.pdfIn PDF document text
    • https://nstyapi.com/resimler/files/wilubafigilop.pdfIn PDF document text
    • https://okazdedziecko.pl/_files/Media/file/gizapivadudukiv.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/84723669613.pdfIn PDF document text
    • https://partetesal.ir/data/file/12971645568.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///52872727444.pdfIn PDF document text
    • http://rc-saty.cz/gais/image/file/14235178659.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/22874346307.pdfIn PDF document text
    • http://growlink.biz/userfiles/file/83251581603.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1614063f589482---2643387530.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16148dbf6a343a---balegobifisitiwinuzar.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/jrpad32ka27m8vvr62oqm0atlq/fujalabavevomov.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109101353278088.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/96397690253.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/u9796almt4736ja6gd61kmq3sl/81610056503.pdfIn PDF document text
    • https://xn--80aaa1arbfjoe3bzh.xn--p1ai/data/files/53899522663.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/vexomaritezuw.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/tisexavagodepuvokareb.pdfIn PDF document text
    • http://sklepjola.pl/userfiles/file/fakararimefejiralefisesi.pdfIn PDF document text
    • http://jjsgreatescape.com/uploaded_files/userfiles/files/87056106722.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_off0000b61c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB61C 16420 bytes
SHA-256: a12e21c3d77bfca78d19ac8b81bce5d3681e657f4246f38d3180c40fb435b41d
font_01_sfnt_off0000e031.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE031 10756 bytes
SHA-256: 1a8b372c7faf83fc3d71cfcd66224a026626100b9a27e8f1b94fd8eca89a0b79
font_02_sfnt_off0000f927.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF927 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1