Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc99b8d54d791dd4…

MALICIOUS

PDF

81.3 KB Created: 2021-09-07 06:37:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6de247d7c7fe4cf3e03cf5cd83181493 SHA-1: 83a59e137d2bfb48d25f0119c5b5a05fce999759 SHA-256: dc99b8d54d791dd468b23470fb1a6d8251a025aa56cb1ea54ae8cd749ad5ca21
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to compromised WordPress sites and other disposable hosting, likely intended to trick users into downloading further malware. No scripts were extracted, but the presence of numerous external URIs suggests a downloader or redirector pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://allytemp.ru/uplcv?utm_term=adobe+premiere+pro+cc+classroom+in+a+book+2018+pdf PDF link annotation
    • http://studioego.cz/userfiles/file/furix.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e66a2c2f1cd---xipopijizosatakowuluzafi.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/38558435014.pdfIn PDF document text
    • http://openendrep.com/userfiles/files/27469784142.pdfIn PDF document text
    • https://delphin-bau.com/ckfinder/upload/files/76354923974.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6990dbb4be---86075394989.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/36236158419.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bb6a6ec8758---46255514585.pdfIn PDF document text
    • https://agentcctv.com/userfiles/file/pazasazopukuxek.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9033a1f5e0---jujasajifitevi.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16084c6827d8e0---fotara.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c84f6321965---95424930644.pdfIn PDF document text
    • https://latework.cz/soubory/64465995168.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/nogasoguwamekudokokiwe.pdfIn PDF document text
    • http://coalcreekcentenary.com/clients/5/52/52f735e63eff8706e1a2a73a20aef632/File/bepobepixutusexanibimewu.pdfIn PDF document text
    • https://selltoob.in/ci/userfiles/files/30321163858.pdfIn PDF document text
    • https://ewastexperts.com/userfiles/files/dopamovijit.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/fikiwirirunozuki.pdfIn PDF document text
    • http://cl-metalparts.com/d/files/tixonogegeliterirafewef.pdfIn PDF document text
    • https://wildnaturetravel.com/File/sosifafudizejigovew.pdfIn PDF document text
    • http://stilna-ya.com/_userfiles/file/takesopavopamozuwu.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_off0000d16b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD16B 11400 bytes
SHA-256: 98c804aeb127052d707fe6dfa9be058ade0d4eb7741e9c34de2b10fa3f615fce
font_01_sfnt_off0000ec18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC18 20100 bytes
SHA-256: fffa3b2708cd3e671b98856ae3e9a758837777f4bde3a5c5bbc6ad8274ccc278
font_02_sfnt_off00011fc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FC9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1