Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d0f8484c6ec243…

MALICIOUS

PDF

82.5 KB Created: 2021-09-22 10:46:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 5257bfd3fdac718b8619ac15e50ee08e SHA-1: c1d4c08394a05eb94034d1a4fb7c88c635360cb5 SHA-256: 81d0f8484c6ec243a94ae2dc5a90df0ce0950e671604313184e395b8764d3426
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm hosted on compromised WordPress upload directories, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous links to potentially compromised sites strongly supports the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/o7pe644o3rn51o0jk1q6qfnns0/refefovarese.pdf In PDF document text
    • http://solarexperte.ch/fckeditor/editor/images/file/lowaweboni.pdfIn PDF document text
    • http://kingkady.cn/uploadfile/files/91235962471.pdfIn PDF document text
    • http://qapoll.com/2015/vat/upload/files/kuleguxilofipovuju.pdfIn PDF document text
    • https://asoriofrio.org/ckfinder/userfiles/files/lunibevomegetukad.pdfIn PDF document text
    • http://villaelen.it/userfiles/files/zisegeviwadejutovokoz.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a8356f08a8---87569117309.pdfIn PDF document text
    • https://vishalahospitality.com/ckfinder/userfiles/files/22799120808.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ad4e767aac---79115248398.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16133579c99eb0---wigofikeveminosu.pdfIn PDF document text
    • https://licorne-hotel-restaurant.com/userfiles/file/83384801154.pdfIn PDF document text
    • http://n-production.com/upload/fckeditor/file/gololen.pdfIn PDF document text
    • http://w-mill.jp/images/file/57683170318.pdfIn PDF document text
    • http://notar-frings.de/userfiles/file/bukeluwegosipofarevagewom.pdfIn PDF document text
    • https://www.le-domaine-de-hauterive.fr/ckfinder/userfiles/files/20978227232.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/96702205796.pdfIn PDF document text
    • https://serihosting.com/calisma2/files/uploads/58909841129.pdfIn PDF document text
    • http://patriabrno.cz/userfiles/files/tojudozevuwovenuzo.pdfIn PDF document text
    • http://ustunongel.com/image/files/90483867049.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161403d090c305---34118214158.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/16144b3772a8f6---ruzobaliwen.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614989560efb4---62917378060.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1613235ae99c89---lutesalefitigego.pdfIn PDF document text
    • https://inijariku.com/ckfinder/userfiles/files/81143353488.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613748bb8b3c9---4990258273.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=mac+tab+between+chrome+windowsPDF 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_off0000dbc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3DB 18280 bytes
SHA-256: 0e9ca12463da5f8ce462ecddafb40e7b55816d87c589dbff456589da4fee6d75
font_02_sfnt_off00012318.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12318 10808 bytes
SHA-256: b32bd8dedb16d1a29bb7cd9540e834064a2245e6f8a2a3b26015f5e7eeee8821