Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc5fd87fe0020bf8…

MALICIOUS

PDF

75.9 KB Created: 2021-09-18 09:13:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bc0d78b17315182e04e1cc8169bbade1 SHA-1: 4e24a379ad0a4ee64c7acddfdf358f8ad68ba060 SHA-256: fc5fd87fe0020bf8e55571a30a121cd07f9addb7fcb13efede195dafb6db588d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan. It contains multiple heuristics indicating it is a link farm, with many URLs pointing to compromised WordPress sites. One heuristic specifically mentions a link farm pointing to compromised CMS upload storage. The presence of an embedded JavaScript stream suggests the PDF is designed to execute malicious code, likely to download a second-stage payload or redirect the user to a phishing site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://wastran.ru/uplcv?utm_term=xx1+movie+app PDF link annotation
    • https://vmgeducationtrust.org/home/vmgedu/public_html/public/userfiles/file/ripobiresapavativapu.pdfIn PDF document text
    • http://cottoneauto.it/userfiles/files/12095745328.pdfIn PDF document text
    • http://piri-piri.pl/ckfinder/userfiles/files/kujafosuzo.pdfIn PDF document text
    • http://www.scea.edu.mn/ckfinder/userfiles/files/22906110079.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/fivadawetafuwope.pdfIn PDF document text
    • http://orikon.net/Images_upload/files/20502338012.pdfIn PDF document text
    • http://zerosquareonline.com/file/22232003644.pdfIn PDF document text
    • http://jingyilin.org/uploads/file/71545688747.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613127512c97b---40396455418.pdfIn PDF document text
    • https://artasedanasingaraja.com/uploadfck/file/39701901686.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/buwikiv.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/4b4a6a91b2c734a94f933ecf41d33ffc/mazoxolabosuwemeroxavi.pdfIn PDF document text
    • https://www.bankkartya.hu/js/ckfinder/userfiles/files/98192484782.pdfIn PDF document text
    • http://travellightnepal.com/userfiles/file/82870111137.pdfIn PDF document text
    • http://teleinwestor.com/userfiles/file/pufupujew.pdfIn PDF document text
    • http://thcsnguyenvanhuyen.hoaiduc.edu.vn/ckfinder/userfiles/files/25806275026.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/67691471068.pdfIn PDF document text
    • https://holyfamilyhospitals.com/ckfinder/userfiles/files/16103460413.pdfIn PDF document text
    • http://visusmarble.com/images_upload/files/tijiwu.pdfIn PDF document text
    • https://crownprolaw.cn/userfiles/Proj_Name/files/49701691209.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16133c26a718a2---juwugijuvoxa.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/70471720041.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_off0000c637.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC637 10124 bytes
SHA-256: ded63dbeea6751a0c4d2f3cbe8994eae265823649b1e5b160ed861a43ea9243b
font_01_sfnt_off0000dcd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E2 17512 bytes
SHA-256: a0574ff6c7a8ffd4f027ffd5c818c3f5e6ffa19456ae3fca2557478a639cb570