Malicious PDF — malware analysis report

Static analysis result for SHA-256 631ba07f1e9e0fc0…

MALICIOUS

PDF

91.9 KB Created: 2021-06-29 22:23:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 62fd1f048e10de1f74d30c15309cd483 SHA-1: b95b876e6b0f1f226dde113447e4e2988de618e9 SHA-256: 631ba07f1e9e0fc0ce5a4645a134320ec68e24f3529286228c51a62488f1caf7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains numerous links pointing to compromised WordPress sites, suggesting it is part of a link farm designed to distribute malicious content or redirect users to phishing pages. The presence of these links indicates an attempt to lure users to external, potentially harmful, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/80p6ftnn39tpva4c92bugvfo3a/37699651618.pdf
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078d82f039c0---vilonovujaji.pdf
    • http://waterreducer.cn/d/files/83908894488.pdf
    • http://hart-metale.pl/gimnazjum/userfiles/file/37782142891.pdf
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/qbaco5e4vso29o4diolfvafv99/97290199926.pdf
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/f1866ffd38e58578469d2d468c7a8335/sakifojozuvizabumis.pdf
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/81ab8225e12defa1d3b58bfb34151112/fudifazoj.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c593d832f1---wavujepujesogavotibi.pdf
    • https://www.adilaltinsoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d82466882d---85658523048.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/vmppfdrkbtrfj3d11ti5cf0ps4/69466320594.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b1d643903e0---86300894324.pdf
    • http://poorclarescork.ie/images/nexogasomuvugovinumikevo.pdf
    • http://magnachip.cn/userfiles/file/20210511031757.pdf
    • https://anmimar.com/royal/userfiles/file/39763994389.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/b32e253f1a1e2551293f551e339382ee/13833410299.pdf
    • http://hillandcunnreunion.com/clients/864369/File/fixolexubunedavexoreb.pdf
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/2ec843a42a1a30c5dd96b8427c9621c9/85769363248.pdf
    • https://korovin.org/site/img_ufiles/67292509734.pdf
    • http://aal.tw/uploads/htmlupload/files/zexitinuludaraj.pdf
    • http://patroha.hu/file/rudawozajetibajonebovadi.pdf
    • http://salkim.com/userfiles/file/raxofugazopuvasaxoditir.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/13b93q4u6a636k7o179sfdtk16/fiwukeg.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c2549304d24---vamezigogoxidevuremek.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-4-29/20210429200941916686.pdf
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/3a3e4f335347cbb8f5037014adcc6f6f/99846177246.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c29981f0d2f---87324891061.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=holy+bible+in+tamil
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010419.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10419 16792 bytes
font_01_sfnt_off00011c2b.bin
742bc93765e7271590b35273c8583115c57504e0da5c3483f4c41a15ec6dff1a
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C2B 18008 bytes
font_02_sfnt_off00014b41.bin
3aebfadd6137bc3c5b8ee62dc1d879833ce52bfc09b6028aa54a27765b1952c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x14B41 10244 bytes