Malicious PDF — malware analysis report

Static analysis result for SHA-256 c73389b147b7b111…

MALICIOUS

PDF

78.3 KB Created: 2021-09-13 23:38:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c2ea62c0671d58c17450011e30f9cad0 SHA-1: 4fbb43f88793b0ac208f7f0e5056ead355360bb4 SHA-256: c73389b147b7b111a455075623d3b0724316340a7864933a71942167abb9adb2
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress uploads and disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were extracted, the structure and URL patterns point towards a malicious document designed to lure users to external, potentially harmful, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 https://smartcirclegroup.com/userfiles/file/97281032628.pdf In PDF document text
    • http://imhyuk.com/imhyukeditor/userfile/file/lufififefobumowobeko.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/kekorusunukamikuzog.pdfIn PDF document text
    • http://avsa.org/sites/default/files/images/files/tekilikodosanuxone.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/rokab.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/74732527850.pdfIn PDF document text
    • http://zavalinka.by/var/upload/file/86695049043.pdfIn PDF document text
    • http://zamdq.com/filespath/files/20210910160734.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/8b43f35835ca79b26c052c4d1d1d9795/57868176180.pdfIn PDF document text
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/bosagodafibixizekoj.pdfIn PDF document text
    • https://illustrations.noche.fr/images/files/62775563864.pdfIn PDF document text
    • http://villkasz.hu/editor_up/kipalafunozabimexerow.pdfIn PDF document text
    • https://icoachyou.biz/images/ckeditor/files/40298124084.pdfIn PDF document text
    • http://phupmirpol.pl/userfiles/file/87871316641.pdfIn PDF document text
    • https://selispin.com/calisma2/files/uploads/25265631260.pdfIn PDF document text
    • http://zenkatsu.dk/files/30403464252.pdfIn PDF document text
    • https://groupburuemas2.com/contents/files/tamazuzomanod.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ac35acfae---vezobawekewoxidon.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/qh5dfpsd0dgr00l39c6dv78hmh/36534469439.pdfIn PDF document text
    • http://stmarysharipad.com/userfiles/file/zedudunuvulitu.pdfIn PDF document text
    • https://duragloss.pl/userfiles/file/78081529428.pdfIn PDF document text
    • http://barexkft.hu/userfiles/file/58727734531.pdfIn PDF document text
    • https://thehideawayresortpattaya.com/userfiles/files/68297457037.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=boruto+dub+full+episodesPDF 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_off0000cb51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e363.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE363 18540 bytes
SHA-256: 666881c246fcafd776b94c02293ceed3e8f76b547692d7186f3fb7f227033def
font_02_sfnt_off00011402.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11402 10516 bytes
SHA-256: 196e8b9e740f2b93d00f62833bb4d514d5c465c48fdcbb824682f1534272249d