Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8bf4011ecb905a6…

MALICIOUS

PDF

88.4 KB Created: 2021-09-14 06:27:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 161e412872cc2d30ecda687a6cfc22cd SHA-1: ac3e0e4dc3a096a77ed307777760f636a44cbe82 SHA-256: b8bf4011ecb905a6e4827e395a13e263691d1880a90b768643fa911c3dcb058f
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Multiple URLs were extracted, some pointing to compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The document body was unreadable, but the heuristics strongly suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://bellina.pl/userfiles/file/narefirogopul.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613671d2bc483---11899457125.pdf
    • http://lyzebrno.cz/userfiles/file/40557441666.pdf
    • http://indyskischool.com/ckfinder/userfiles/files/gumapigalalewuxe.pdf
    • https://growyourmoney.in/userfiles/files/1447501305.pdf
    • http://rurisnet.org/images/file/1067116826.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/54d2a478119983d8d7c0c97b4c8d35c0/62389159178.pdf
    • http://galluccifaibano.com/userfiles/file/23174182336.pdf
    • https://majorsagilekvaros.hu/uploads/file/46889011888.pdf
    • http://johnmarzillier.com/ckfinder/userfiles/files/37181426277.pdf
    • https://giriconsultancy.com/content_files/files/varotapufa.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613532f971113---zemedobokonobote.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/0132b3bc874e1a57db95fff8a9f60977/rokukofabudaru.pdf
    • http://webinaris.org/ckfinder/userfiles/publics/files/70506959260.pdf
    • http://maxidmum.com/images/upload/fck/file/burugetujimebenovewo.pdf
    • http://airmon.hu/images/files/folemob.pdf
    • http://ahjygjg.com/upload_fck/file/2021-9-6/20210906030333937686.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/invap3ub1hm8s1q8bvk9podlr4/gugagip.pdf
    • https://megatex.ua/images/uploads/file/40553940288.pdf
    • http://giaexploring.it/userfiles/files/26524409210.pdf
    • https://iagclaims.endataclaims.com/ModCoreFilesUploaded/file/rabufarurez.pdf
    • https://cortemadera.com/wysiwygfiles/file/silutu.pdf
    • http://saharun.org/uploads/ckfinder/userfiles/files/jisekazesexebozo.pdf
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/16139bb370a5dd---12224997452.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+transfer+game+center+to+android
    • 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_off0000f682.bin
97a1e749ad91397b6765ca13ecff81586d730e830f83009c9019f3e8f92a8c8a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF682 16960 bytes
font_01_sfnt_off0001229b.bin
2d506b710e08086ef324bd2b2f133c688ed538f7b06caef65840c7321ca3104d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1229B 10848 bytes
font_02_sfnt_off00013b75.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13B75 16792 bytes