Malicious PDF — malware analysis report

Static analysis result for SHA-256 728cff988837eac7…

MALICIOUS

PDF

67.8 KB Created: 2021-05-28 18:12:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 9d32a351ea1ef2d01e6b0663c601056d SHA-1: a98b0c08fdc3a2e28c7bb40a1fa50ff9dcb93c0a SHA-256: 728cff988837eac7674b0f47e948886b888cc3e23abee3acf499ba90b2ecb989
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://crewmak.ru/uplcv?utm_term=what+is+tcp%252Fip+and+udp PDF link annotation
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/2545c859d22086d7ae471a385b431e80/wuteruninizowe.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/1c9r6ms0gj74brlekj1vh72231/kukuvitimurixapitaroko.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/98a8697fa4a3b5680982ecb0b90d4a11/fujuronekusexowosevite.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160853676dabfd---39028277702.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16070c42cc8a0b---45627210980.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8f512976c---96261575870.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/df4bc6e64c1541bccebe1cb1ef050622/59694769584.pdfIn PDF document text
    • http://maychamsocda.vn/images/userfiles/file/35167856115.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/er5mcd14gd8e1pbakcu5hsili6/jiwewivutivobemar.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/2d2d932f0df67d06685557890d0c1fcc/kopovodifisavuz.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/xetemala.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083ebe8532d6---12508781939.pdfIn PDF document text
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/6q5appjfp014fuk1g3b73m7df7/gonapufibuvuvip.pdfIn PDF document text
    • https://tavio.ru/files/file/fuguvupurovagenemawotutu.pdfIn PDF document text
    • https://aimhc.com/userfiles/file/belufiwizilulubosotakazel.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB71 5080 bytes
SHA-256: 140d3d59264f0ade7465a6b1c9517f45c3f162de47bd4500f6fd90eef6e0f89d
font_01_sfnt_off0000dcd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD1 12440 bytes
SHA-256: 0a3e423c6519d9933cbcd4c48a1f2afd1e8d722e98c3bbdb6634f1d42d2503c7