Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a73e736bce4e15d…

MALICIOUS

PDF

85.4 KB Created: 2021-09-13 03:02:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b1a3edf5a95a30647a7cf8994167c4fe SHA-1: 24aa7edf80ff82d0655bf7966160e7162212ff21 SHA-256: 4a73e736bce4e15d577cdf9fccbb9f7a397868e406cca227063722fafe74cb7b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains a link farm with numerous URLs pointing to potentially compromised websites or disposable hosting, likely intended to redirect users to phishing pages or download further malware. The PDF structure and embedded links suggest an attempt to exploit users through deceptive content, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://nomylo.ru/uplcv?utm_term=telugu+movies+free+download+sites+hd PDF link annotation
    • https://sssmri.com/ckfinder/userfiles/files/jukowajedexutadovu.pdfIn PDF document text
    • http://armanetti.com/images/46272164132.pdfIn PDF document text
    • https://balarampurblock.in/ckfinder/userfiles/files/raseretag.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///56903248334.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/nimewa.pdfIn PDF document text
    • https://rgcsmt.org/ckfinder/userfiles/files/gawarosibixanosalasefoz.pdfIn PDF document text
    • https://generalaudit.pl/eurostyl/photos/file/92724751079.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/9186051502.pdfIn PDF document text
    • http://cayxaotamphan.net/userfiles/image/file/wuwemofaxagujetunolutona.pdfIn PDF document text
    • https://hijaustabilo.com/contents/files/jimejotimajogaze.pdfIn PDF document text
    • https://www.jnvhardoi.org/ckfinder/userfiles/files/58058379518.pdfIn PDF document text
    • http://aisne.proximeo.com/ckfinder/userfiles/files/zokoke.pdfIn PDF document text
    • https://serihosting.com/calisma2/files/uploads/50432407244.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/hh88qpia0ui2192h8vk3akk5k1/waviwonaripajotituselob.pdfIn PDF document text
    • http://bsinteriordesigner.com/userfiles/files/vinajitimepinapegonez.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16131da206fe27---pinowe.pdfIn PDF document text
    • http://www.scea.edu.mn/ckfinder/userfiles/files/65187343412.pdfIn PDF document text
    • http://teknis.it/userfiles/files/gipiluxurenev.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f461554dd---bojagexixidizuven.pdfIn PDF document text
    • http://misosmile.com/upload/editor/files/xawevuxozewivaza.pdfIn PDF document text
    • http://pb-book.com/user_file/file/56218080081.pdfIn PDF document text
    • http://bona-agra.pl/Upload/file/kotomeni.pdfIn PDF document text
    • http://pune-india.info/userfiles/file/gekitozeduvavijeraza.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_off0000eaa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAA0 11016 bytes
SHA-256: c83909292cc3efeda7320407e6faa8bb28485aa6335ab86d89d0477b2429bdce
font_01_sfnt_off000103e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E8 17092 bytes
SHA-256: 618c4f7004136e50dc4c813658f90f96c3a540323073cd9faa00a8c1db809f06
font_02_sfnt_off00013015.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13015 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1