Malicious PDF — malware analysis report

Static analysis result for SHA-256 763c339f8850ac45…

MALICIOUS

PDF

82.5 KB Created: 2021-10-10 02:03:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 51274edbe113e2617548c696cf3ce0e4 SHA-1: 17d788ac1d42d04c77f3941288e7e4f258367515 SHA-256: 763c339f8850ac451b820ea3aef521257f9dde07a388ddc44ceb8d6dd97bbb11
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics identified the PDF as a link farm, with many embedded URLs pointing to potentially compromised WordPress sites or disposable hosting. These links likely serve to redirect the user to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://laborke.ru/uplcv?utm_term=six+letter+words+starting+with+k PDF link annotation
    • https://krygina40.ru/UserFiles/File/43601596998.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efd871638a---15440697483.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/70134458885.pdfIn PDF document text
    • https://onecre.com/images/content/files/retuwusajo.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/71278138264.pdfIn PDF document text
    • http://centromp.it/userfiles/files/vamajulirulir.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/96078097000.pdfIn PDF document text
    • http://maivietnamesecotati.com/uploads/files/zivudokawe.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16153e19e8dd87---dipatujejatuwuzetogu.pdfIn PDF document text
    • http://goldenstarhotel.vn/images/uploads/files/lijepigepizutunabiz.pdfIn PDF document text
    • http://bjqyms.com/filespath/files/20210927141355.pdfIn PDF document text
    • http://zhatuogz.com/uploadfile/file/81527186441.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/bd653994d7fd34456952bc95c3118a03/nanejesitomawuguri.pdfIn PDF document text
    • http://loca-granderoue-montaletang.com/ckfinder/userfiles/files/76154081585.pdfIn PDF document text
    • https://kfk-dekoration.dk/images/uploadedimages/file/74853002248.pdfIn PDF document text
    • https://nilsahost.com/calisma2/files/uploads/muzipugexufowilifaxoj.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16135213cc385c---kawore.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/6e3a755aa72c5e201938f9acc5216551/19423354646.pdfIn PDF document text
    • https://gryf-wet.pl/ckfinder/userfiles/files/88971373673.pdfIn PDF document text
    • http://tupnate.com/ckfinder/userfiles/files/foxonitadadurilawopepu.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_off0000d014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD014 22976 bytes
SHA-256: 277ae7c0f5b3fadfd8526e594c59871f8050f85556f8b5104926f078935cfdad
font_01_sfnt_off00010b4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B4E 10884 bytes
SHA-256: 3a484633d432ed0f82a4f5da986c176a159f1ee7210c6667833518af1c16b7cf
font_02_sfnt_off00012441.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12441 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1