Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8cb55dd6429be09…

MALICIOUS

PDF

72.9 KB Created: 2021-09-22 17:07:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d46c78709c261031e9b2f85147d3bbce SHA-1: 221b03de5cc136b4180734d71eef40bbc66591af SHA-256: b8cb55dd6429be0921e017b5dbbcedf5645f83b94824ed1630a59ce987b12f15
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to compromised CMS upload storage, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://cructi.ru/uplcv?utm_term=facetune+download+free PDF link annotation
    • http://bbmpva.nl/fckassets/file/16381736720.pdfIn PDF document text
    • https://psg66.ru/admin/ckfinder/userfiles/files/refoxes.pdfIn PDF document text
    • https://altinhediyeler.com/calisma2/files/uploads/7231103576.pdfIn PDF document text
    • http://shahgrp.com/uploads/4675939150.pdfIn PDF document text
    • https://aluvioneschicamocha.sinecsas.com/ckfinder/userfiles/files/15212069275.pdfIn PDF document text
    • https://suncables.co/images/file/nujixedufokegujijefoku.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/57085543251.pdfIn PDF document text
    • http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/40966547277.pdfIn PDF document text
    • http://harnettcountyhba.com/userfiles/file/13677043402.pdfIn PDF document text
    • http://pkpneu.cz/userfiles/file/35518667082.pdfIn PDF document text
    • http://silverspringabw.com/uploads/files/bebeni.pdfIn PDF document text
    • http://mnogonomerov.ru/uploads/file/minusevuwimusisar.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/misowokibo.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/16139a2f10bf9a---jozudowidakufi.pdfIn PDF document text
    • http://xn--9w3b11kh5l.com/ckupload/files/divaloralokuki.pdfIn PDF document text
    • https://htijsr.com/userfiles/file/95087565150.pdfIn PDF document text
    • http://qdjshg.com/files/file/lutotifenufisa.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142dac309735---luvofudinokiluxobujivafun.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/pusuxesurujumufuk.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/143c72d10395abc5db994591fb1673fb/kivov.pdfIn PDF document text
    • http://leaders-adv.net/userfiles/file/10252248721.pdfIn PDF document text
    • http://xn--90afqerdlt1f.xn--p1ai/admin/ckfinder/userfiles/files/jatozotox.pdfIn PDF document text
    • https://planet-pvc.com/upload/files/62135590617.pdfIn PDF document text
    • http://dungcubepgiangtrinh.com/webroot/img/files/53846658731.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_off0000bb46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB46 16824 bytes
SHA-256: 70daf67bff31ff990345a3ead33ba237c364b40313893c0217b0ca863e003bc8
font_01_sfnt_off0000e683.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE683 10372 bytes
SHA-256: 0a49f7dddb340cdf6ced59813b2b8b48662bb994b84d97d641809a85821c40e3
font_02_sfnt_off0000fe2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE2C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1