Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb9743b78085ea9f…

MALICIOUS

PDF

70.7 KB Created: 2021-09-13 21:07:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c862e7778a6e9ec517694c3822de4c5f SHA-1: 40e50f70e28d3a9afe1440af72b797b4c0d19586 SHA-256: cb9743b78085ea9f1e51801792d2b9f75f26b66ff868eecbafd3bcc415141d0d
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting it functions as a link farm to distribute further malicious content. The presence of external URIs and link farm heuristics strongly supports a phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://hichipper.com/hichipper/uploadfile/file/2021091105265673499.pdf In PDF document text
    • http://pcwenhua.com/uploadimg/file/1630522288829133692.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/16135bb83c3cf0---magimobirafajevon.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/ee49779f29259ca7cc6e31b96c51d39b/30139131992.pdfIn PDF document text
    • https://hunghiephuylog.com/upload/files/26825162252.pdfIn PDF document text
    • http://pokrowce-ochronne.pl/Upload/file/gidaduri.pdfIn PDF document text
    • http://pxmonastery.org/CKEdit/upload/files/jigusogesafel.pdfIn PDF document text
    • http://studioindelicato.com/userfiles/files/sazipazolalulodewaxalu.pdfIn PDF document text
    • https://sofahatinh.com/upload/files/kejiwoxo.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/lobogowuvewibozutefuwuben.pdfIn PDF document text
    • http://thsport.dk/ckfinder/userfiles/files/dimopolunoliva.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/4jegnjbkr5ghlis2unnqc7vf5g/sebigasitaramil.pdfIn PDF document text
    • http://harmonie-avion.fr/actualite/files/90086114770.pdfIn PDF document text
    • http://ventss.ru/userfiles/files/87068190344.pdfIn PDF document text
    • http://yossy.biz/userfiles/file/wozuxutofejerububojuru.pdfIn PDF document text
    • http://ndc-group.ru/uploads/files/zixunijisiwu.pdfIn PDF document text
    • http://chinasoftcore.com/userfiles/file///51292100549.pdfIn PDF document text
    • http://morard-mcf.fr/data/Files/51118775110.pdfIn PDF document text
    • http://keralastatetailorsassociation.com/userfiles/file/vumemuxebizunezemevab.pdfIn PDF document text
    • https://manorhair.com/uploads/files/202109100956171346.pdfIn PDF document text
    • https://alpinashop.rudy-ra.com/files/11217773853.pdfIn PDF document text
    • http://zatacorp.com/upload/files/84424643558.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=watch+angel+has+fallen+full+movie+onlinePDF 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_off0000b1b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1B1 16488 bytes
SHA-256: 490a2273b6686a65d039fb9ae9b988a96306bda89c2c9bb7ddc4269a883072a5
font_01_sfnt_off0000dc63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF47A 10844 bytes
SHA-256: 67dec42946d648fd3ab1880ae42a475500f1ec73fe302b8fffcff0499c1832ee