Malicious PDF — malware analysis report

Static analysis result for SHA-256 98c203b5e4ec3ba1…

MALICIOUS

PDF

78.6 KB Created: 2021-09-05 03:58:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4a761f7b461f1386e05101821814aac8 SHA-1: b1c71bba697ba757a70c9e7912c99621c964b310 SHA-256: 98c203b5e4ec3ba18ffdf527e6b8c96d1709b986e0fc9f9e10762633da78e534
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to potentially compromised websites or disposable hosting, indicating a link farm designed to redirect users. ClamAV detection as 'Pdf.Phishing.Trojan' and ML classification further support its malicious nature. The primary attack pattern involves luring users through a spearphishing attachment to a PDF that hosts a link farm, likely leading to phishing pages or malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://silesiacapital.eu/data/file/25258603928.pdf
    • https://altonika.pro/files/fck/file/wabomidupurukitamofeje.pdf
    • http://thucphamchucnangmy.vn/uploads/files/detaposilizodesezanebik.pdf
    • http://concilianavarra.com/userfiles/files/xegori.pdf
    • https://heyratacademy.ir/file/27085071391.pdf
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/2fa25acdf160574db8ce4101cbcf1c39/58528869887.pdf
    • http://viprealestatebrokers.com/userfiles/files/40276523566.pdf
    • https://actor-conseil.com/files/file/kunufelawibuwavuk.pdf
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d452a3d199---fusis.pdf
    • http://www.adarshvidhyasankul.org/userfilesfile/nowiwo.pdf
    • http://tatugigo.com/ckfinder/userfiles/files/98771072132.pdf
    • https://promenade-perpignan.com/userfiles/file/44683244732.pdf
    • http://littlepearlbooks.in/data/eimages/file/vamuk.pdf
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/16081716322293---65347468024.pdf
    • https://neksav.com/upload/ckfinder/files/40399001184.pdf
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609dcd4487073---20677367837.pdf
    • http://studio70.eu/userfiles/files/65881429491.pdf
    • http://alnadaoil.com/userfiles/file/sofafo.pdf
    • http://lawngo.net/fckfiles/32449125827.pdf
    • http://colorfusion.us/admin/images/file/38655158918.pdf
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607a2687738aa---puwexisekavukoni.pdf
    • http://cascinamana.it/userfiles/file/gosanipufipenamakobiwulaz.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=mail+merge+from+excel+to+word+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf42.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF42 16792 bytes
font_01_sfnt_off0000e759.bin
aa68afdff49de3d79b3d2d2b8bfd7e832d4de9114a025942690bace9a7fe83a7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE759 10872 bytes
font_02_sfnt_off0001004f.bin
dd8084761bd65f91b13a5bf19ec0a2198664df6991d72f50e095c6385b582c59
pdf-font-stream PDF embedded font (sfnt) at offset 0x1004F 17052 bytes