Malicious PDF — malware analysis report

Static analysis result for SHA-256 11af7f781abc703f…

MALICIOUS

PDF

82.1 KB Created: 2021-09-23 22:03:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: caf476c22470fdd3ece290213a502c49 SHA-1: bd2a5d1113b3d306cc9b324581f6b3298a09bdde SHA-256: 11af7f781abc703f63de82aa8ca8599ecc06bd038902b116b7d91c1d07fad465
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. The presence of numerous PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics confirms this behavior, suggesting the document's primary purpose is to facilitate access to malicious content or phishing sites.

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://philabc.ru/uplcv?utm_term=bypass+ssl+pinning PDF link annotation
    • https://wigs4less.net/nbloom/fckuploads/file/75475227508.pdfIn PDF document text
    • http://www.naraihillgolf.com/admin/userfiles/file/7901788031.pdfIn PDF document text
    • https://aluminiosarla.com/userfiles_arla/files/37295749935.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/c007199cba08addf9ceabbbe3d08c154/zefizabapusobevida.pdfIn PDF document text
    • http://www.ondebiz.com/userfiles/file/86364582979.pdfIn PDF document text
    • https://villadorottya.hu/uploads/frontend/files/15057362728.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/k2tvfvtbgaev0jrd5snjgc78v6/xaketovupoxe.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/42833710702.pdfIn PDF document text
    • http://studioingegneriavaragnolo.com/userfiles/files/43660775879.pdfIn PDF document text
    • http://avanti-kuhni.ru/upload/files/melijopibot.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad79bb487a---guwululuju.pdfIn PDF document text
    • https://ladymamashop.com/uploads/files/202109061150238149.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614b618aa0ec4---4868664539.pdfIn PDF document text
    • http://www.de.ruben.pl/ckfinder/userfiles/files/97660916349.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161494509dd295---kowogurojidowifozida.pdfIn PDF document text
    • http://tzsunup.com/upload/gubokisanorimis.pdfIn PDF document text
    • http://potlista.com/file/files/nimesexowole.pdfIn PDF document text
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/30600600431.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/34067191852.pdfIn PDF document text
    • http://floridadressyourhome.com/uploaded_files/userfiles/files/693681450.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/d490d475c6af00c7cf8e1bf337b274fe/81900621914.pdfIn PDF document text
    • http://giahung.tincorner.com/uploads/files/98668966239.pdfIn PDF document text
    • http://nhahanghienminh68.com/upload/files/9230618312.pdfIn PDF document text
    • https://agriplan-rs.com/dados/ckfinder/files/nopizupewodexamajewavozal.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_off0000df94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7AB 10144 bytes
SHA-256: cea7fcb15f2856916c10a8b8f92ad7482de0e2ec312337096d7fc0d595c592f9
font_02_sfnt_off00010e6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E6A 17460 bytes
SHA-256: a7c97b8fbb4fd8b8aa736153508a83e818256f74af7f012dea0d77f3f9e14f4a