Malicious PDF — malware analysis report

Static analysis result for SHA-256 82b75572715c635a…

MALICIOUS

PDF

80.7 KB Created: 2021-09-12 01:33:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 74c63bd4f692a867ea09aa7367b5db42 SHA-1: 3909316111cfd8be32dac0ca266d68cba737b220 SHA-256: 82b75572715c635a9dadaa7588bf17f65875c9889a4a0926cd554e9c94ffe160
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate this is a link farm designed to direct users to external sites, with one URL specifically mentioning 'secret call recorder pro apk', suggesting a lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://synerhu.ru/uplcv?utm_term=secret+call+recorder+pro+apk PDF link annotation
    • http://caycanhtuyhien.com/uploads/image/files/84842395387.pdfIn PDF document text
    • https://parlagame.net/calisma2/files/uploads/metoneze.pdfIn PDF document text
    • https://jeneifogaszat.hu/cikkdata/files/dalotarapamumor.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1613738df0bb47---latalisilenegoribubibasod.pdfIn PDF document text
    • http://kernenshepler.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89798371449.pdfIn PDF document text
    • http://coolscape.info/images/files/30667396338.pdfIn PDF document text
    • http://avsa.org/sites/default/files/images/files/jaxipasosojebowes.pdfIn PDF document text
    • https://urbanshapes.in/userfiles/file/butijulefajekoveda.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/6f1ep916ovomg95bgcppquv9q8/28850969375.pdfIn PDF document text
    • http://blueview.nl/app/webroot/files/userfiles/files/92626414279.pdfIn PDF document text
    • http://pensjonatagat.pl/userfiles/file/15404398888.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/33952926579.pdfIn PDF document text
    • https://wanfutemple.urwaydesign.com/data/file/userfiles/files/7678460715.pdfIn PDF document text
    • http://hevolta.com/upload/file/27038529637.pdfIn PDF document text
    • http://jonellchem.com/upload/files/29145307509.pdfIn PDF document text
    • https://bartonsteel.com/tony/barton/ckfinder/userfiles/files/zulebowunap.pdfIn PDF document text
    • http://seger.cz/userfiles/file/puxijunuto.pdfIn PDF document text
    • http://csc020.com/userfiles/file/20210905111212_w8ev37.pdfIn PDF document text
    • http://bwlpsalisbury.com/uploads/files/wadujonopidivem.pdfIn PDF document text
    • http://saaretravel.ee/images/file/salujakipok.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f101f1f00e---fodotaxujimapesedat.pdfIn PDF document text
    • http://wonderpanel.com/app/webroot/img/file/38497250005.pdfIn PDF document text
    • https://fallahi-sch.com/userfiles/file/pudepojamatote.pdfIn PDF document text
    • https://sydneystudytour.com/accounting/userfiles/file/naxuxi.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_off0000d1e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1E6 19848 bytes
SHA-256: b947cd23150e1521bfa7226fce5208abb161b3fe2e22584877d0291391db8e50
font_01_sfnt_off00010617.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10617 10308 bytes
SHA-256: 8de48718e4cd7af12ea3cfd27da8ca87b0bb20d54e05e13819f66569c4b52bb6
font_02_sfnt_off00011d77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D77 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1