Malicious PDF — malware analysis report

Static analysis result for SHA-256 c856d78373154dd8…

MALICIOUS

PDF

74.1 KB Created: 2021-10-17 22:07:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 6873ac9b71259df4a90bf4e1c8714947 SHA-1: 19f0f9fc34fffdd74b9f6d3e3b870167a83eac84 SHA-256: c856d78373154dd804ef966d617ff84e195a21d632acc2934a51859fb33b77e1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It functions as a link farm, containing numerous URLs pointing to compromised WordPress uploads and disposable hosting sites, likely intended to redirect users to malicious content. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1614f5b5b457f1---96170780302.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131743b52fc2---37147492364.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/2021913035135246.pdfIn PDF document text
    • https://khabul.mn/mmpa/userfiles/files/93434744188.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/texumoduvoburatamowepavev.pdfIn PDF document text
    • http://lynxitservices.com/ckfinder/userfiles/files/33473972580.pdfIn PDF document text
    • http://usmleworkout.com/files/file/feporulo.pdfIn PDF document text
    • http://lnyuanzong.com/uploads/files/20211018025516.pdfIn PDF document text
    • http://spartapr.com/images/upload/file/24806621493.pdfIn PDF document text
    • http://seteo-dechets.com/images/file/sadebubuxinezunudiso.pdfIn PDF document text
    • http://prefinancovaniehypoteky.sk/res/file/85149370780.pdfIn PDF document text
    • https://dortmundpools.com/contents/files/34371285497.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614cf584e88e1---91045043355.pdfIn PDF document text
    • http://manpukulivermore.com/uploads/files/96033342159.pdfIn PDF document text
    • https://nycsmindia.org/ckfinder/userfiles/files/52270604226.pdfIn PDF document text
    • https://www.mmgrowersg.com/ckfinder/userfiles/files/59462717862.pdfIn PDF document text
    • http://www.taxivanclass.com/uploads/ckfinder/files/88504374690.pdfIn PDF document text
    • http://creative-format.com/upload/editor/files/seduwefukipixipotalix.pdfIn PDF document text
    • http://pharmorgsyn.com/upload/files/zizujawejajoxepegetug.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161380a57f1bae---61084154124.pdfIn PDF document text
    • http://bhartiyambeohari.in/userfiles/file/wifupunobe.pdfIn PDF document text
    • http://klwas.org/userfiles/images/file/84261880691.pdfIn PDF document text
    • https://kenkochaya.com/user_data/ckfinder/files/lepexirixojeve.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/gategafowosusa.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/Z3ufxtS7Wvw/uplcv?utm_term=one+mole+of+non+ideal+gas+undergoes+a+change+of+statePDF 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_off0000baa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAA1 11048 bytes
SHA-256: 87dcf30ab9e340f1ee8d2aa47c29ba0fa9a807fceeefa0a8371c764a1446e13f
font_01_sfnt_off0000d3f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC0B 17764 bytes
SHA-256: f03403176d0a03d79f5fe339b3e96ec697403ece12d18b1ad30c6242e591adc8

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