Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c8a3faf8d587753…

MALICIOUS

PDF

103.9 KB Created: 2021-08-20 11:24:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 23f990ea48bec6dbd1fb16068823d3e5 SHA-1: 444838a0dff31f75e34507e720ee49f2642baad2 SHA-256: 4c8a3faf8d5877535c2eb2c436c5030e3fbc1203da5a0d7a6a0d9a40c6e156a8
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised websites and disposable hosting, suggesting it's part of a phishing or malware distribution campaign. The PDF structure and link farm heuristics point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://alnoorcity.com/userfiles/file/498955679.pdf In PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3b36468bc5---vimatagunipafukofokajesis.pdfIn PDF document text
    • http://ebd.su/UFD/7623/files/zatanowaxajur.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c90e7e89ab9---gadoluji.pdfIn PDF document text
    • http://synthecinter.com/userfiles/files/52655013949.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/d37a8acd761cea1465ec4b02c86ba9e0/14792805933.pdfIn PDF document text
    • http://kalmi.ru/upfiles/files/63761185042.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160d45832eebf4---vijetamiporumuf.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfcbcb755ca---76529719865.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/b321e34a7b793b0810289781ee269fde/febakutamebomi.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4be077bc74---6297815874.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/bb6a3ab965672f279b43f407a6eb2548/nazamesosorasipi.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/8ce5eb6d18950cc073c2df9118bd6166/38192848672.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/nolonuzaxagixog.pdfIn PDF document text
    • http://sungsam.net/userData/board/file/88740979514.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/65687219493.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608686db0fa3b---1670458291.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0baa82193c---xefapasupar.pdfIn PDF document text
    • http://www.conectadoscomdeus.tv/arquivos/file/xavesazub.pdfIn PDF document text
    • http://princeverma.in/uploads/files/fewibutibupufaj.pdfIn PDF document text
    • http://personnelstrategies.net/userfiles/file/sibobepefunozinenad.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16072a296e9716---lezijisi.pdfIn PDF document text
    • http://peneleos.pl/userfiles/file/44208612809.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/wixarijifakox.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/tnp8k01kki5rva5ir9unft17f4/6038705137.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=is+mistborn+a+trilogyPDF 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_off000132b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132B6 10524 bytes
SHA-256: 5c97b0141ebb6d30f7c5766850eaa6b5efbc41dfcab995c725981c8b2d740111
font_01_sfnt_off00014aa2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14AA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000162b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x162B4 17760 bytes
SHA-256: 5d555e1728327d6c9ea6599bc289250faa3a32bbc690d8657dbc8e961377c83b