Malicious PDF — malware analysis report

Static analysis result for SHA-256 f64cbecd7c160e8f…

MALICIOUS

PDF

75.0 KB Created: 2021-09-18 16:47:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8ec6f0b715ccefac74356579a7c0ef35 SHA-1: 37b2837713cc9d02e8e1f9ea7d1022c4c46c48d2 SHA-256: f64cbecd7c160e8fc4c929c23b1a5bbe44f05cea7563afd8bb6e03edc8ec026e
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. Heuristics indicate it functions as a link farm, with several URLs pointing to compromised CMS upload directories. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest an attempt to lure users to potentially malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://ankaraeksioglu.com/resimler/files/60212368416.pdf In PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/4a92c0eeb326fd591d11a7b33717b443/bufutuji.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/161420103831fe---repavekepej.pdfIn PDF document text
    • http://vinabomi.com/uploads/userfiles/file/tikemodizirofikugudav.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/20719222255.pdfIn PDF document text
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/rudiwoni.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/b2ca8ce0ba451a7a939fe742db153bbf/tevexalupotor.pdfIn PDF document text
    • http://longvu.vn/Images_upload/files/jadowasakejazozivobi.pdfIn PDF document text
    • https://xn--fiqa735be48e.com/upload/files/boripolupadi.pdfIn PDF document text
    • http://arnoldbolingbroke.com/ckfinder/userfiles/files/nogikekovejawesixo.pdfIn PDF document text
    • http://sciattella.net/images/file/zititole.pdfIn PDF document text
    • http://keystoparadise.com/userfiles/files/67164575069.pdfIn PDF document text
    • https://rwd1.thadv.com/upload/files/47822559933.pdfIn PDF document text
    • https://novsport.com/content/File/dujujufakelim.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/32425983352.pdfIn PDF document text
    • http://lawyergz.net/uploadfile/files/9859578698.pdfIn PDF document text
    • http://tbvshungviet.com/upload/files/lafuvelukavekidovisip.pdfIn PDF document text
    • http://adams-gold.ru/archive/image/file/47781785373.pdfIn PDF document text
    • http://physio-praxismitte.de/userfiles/bosetoruvozipivumu.pdfIn PDF document text
    • http://kemnhapkhau.com/upload/files/1240152021.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/jalotogusibu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=minecraft+furniture+mod+apk+downloadPDF link annotation
    • 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_off0000c193.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC193 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9AA 10884 bytes
SHA-256: ad1f62f52e64466e306c16eeb7f610c87c1d4b58e890e30d70bd2d2039c7ba3a
font_02_sfnt_off0000f2de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DE 16940 bytes
SHA-256: 4c136380bf07b46f058f49c7964a3daf41c8d67e8670973905587d8ce0211713