Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bc913a37441c3ff…

MALICIOUS

PDF

88.9 KB Created: 2021-08-13 20:48:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8c970cf78bc88d812a6c8b03b1154bb6 SHA-1: 2763d0c3a31e3dc5c775cc546a8c40d3c3d981fc SHA-256: 4bc913a37441c3ff6d02e38b7a6e88dcb3f4489941b13ba41af14bfed3ae0ca5
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a phishing or malicious redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of multiple PDF-specific heuristics related to URI and link farms supports the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://shatalarab-llc.net/userfiles/files/levipanirogugosivuwadevo.pdf In PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608e6ed0b1dea---gutidonofowipezan.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606e1064bdc49---52990089091.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8469480f91---resilaxazok.pdfIn PDF document text
    • http://hzqzg.com/d/files/sajodevabifa.pdfIn PDF document text
    • http://meteosputnik.ru/userfiles/file/15130963490.pdfIn PDF document text
    • http://kayapaliinsaat.net/file/sobomogadodizu.pdfIn PDF document text
    • https://begili.com/uploads/image/files/59885288387.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/zewomodomup.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/8srd9h2j9941orvv46767l6897/93800476247.pdfIn PDF document text
    • http://meimagedance.tw/ufiles/files/26178309670.pdfIn PDF document text
    • http://suamayin.biz/userfiles/file/tuxogitobe.pdfIn PDF document text
    • https://gofropack.com/wp-content/plugins/super-forms/uploads/php/files/eaa5f80083209a0ac15b19924c4bf7f6/80281185172.pdfIn PDF document text
    • http://101-games.ru/images/uploads/files/nepogivilel.pdfIn PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/pixejiwa.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608032f8e44a1---29404270839.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160d5a13f8c1a3---tudivuligozojazatuwif.pdfIn PDF document text
    • https://martybermanassociates.com/wp-content/plugins/super-forms/uploads/php/files/ce2d3ffbf74b1f5770cd690a08943411/bavesusajarafatapa.pdfIn PDF document text
    • http://anpo.vn/upload/files/29922117714.pdfIn PDF document text
    • http://virtualcharityevents.com/vce_cake/files/files/51900750097.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094ca9d6047f---24527023986.pdfIn PDF document text
    • https://nergizleryapi.com/image/files/luwefonopumixekaza.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210528195901.pdfIn PDF document text
    • https://cafesca.org/ckfinder/userfiles/files/zamezebekarigefuro.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/7fd40305513382189ea5e23bf39e7dd5/zinatotaseroxi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=%C3%A9chelle+dubois+buyse+cm2+cenicientaPDF 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_off0000f160.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF160 11008 bytes
SHA-256: 9ed7d44cc96847f7daec5e675c43901e8fb131a7a359e0c8fc0b773e03742671
font_01_sfnt_off00010ad5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD5 18788 bytes
SHA-256: 45c3f7a8839ca3ede9353484cb56f1db2091577b4eefdc37c2e7ab9135f3bf90
font_02_sfnt_off000139fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1