Malicious PDF — malware analysis report

Static analysis result for SHA-256 9842348923833a3c…

MALICIOUS

PDF

85.5 KB Created: 2021-10-09 03:26:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 66847994ffc6de50d0ef5bbac8ecdfb0 SHA-1: 6f8b1bb7571af2c6fb840e975dacb4f7d12e4dfa SHA-256: 9842348923833a3c5466b4465041a1f556da6eeb23fcd06fcc7cda277289eb41
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of a link farm suggests an attempt to obscure the final destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://ros.by/ckfinder/userfiles/files/4809313562.pdf In PDF document text
    • http://kutyasturak.hu/images/files/bojawosarerakos.pdfIn PDF document text
    • https://danielfelber.ch/userfiles/file/buzigukebebenif.pdfIn PDF document text
    • https://loyd.rs/images/file/renoxisutese.pdfIn PDF document text
    • https://datenglagi.com/contents/files/25791304705.pdfIn PDF document text
    • http://www.taxivanclass.com/uploads/ckfinder/files/5775645756.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/96707602709.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/rigekuken.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/saxunobisa.pdfIn PDF document text
    • http://seanmore.com/userData/board/file/dadefazotanodexemukiralo.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f64162f4de---lagenobujefe.pdfIn PDF document text
    • http://okuninka-biale.pl/userfiles/file/kelokuperalasanofanibo.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1615f9052b545b---jitiragasujakifid.pdfIn PDF document text
    • http://licausi.it/userfiles/files/jifupufipozebux.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/85472695949.pdfIn PDF document text
    • http://studiostocchi.eu/userfiles/files/93617178459.pdfIn PDF document text
    • https://sfeerweter.nl/userfiles/files/22561012908.pdfIn PDF document text
    • http://aweibel.com/Photo/file/tedaba.pdfIn PDF document text
    • http://misterholidaysanprisco.it/userfiles/files/zutalu.pdfIn PDF document text
    • https://kitapkapla.com/upload/ckfinder/files/63234356482.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/6e8fdf1209983ee981632fd3eb1c108d/debipigopenuvuxadabosunem.pdfIn PDF document text
    • https://fond.ru/userfiles/file/nuzidakifimaxupirotovag.pdfIn PDF document text
    • https://mcorretajes.cl/upload/file/pomazexugadutibapakajeza.pdfIn PDF document text
    • http://hycxchina.com/filespath/files/20211002222808.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=highly+exothermic+reactionPDF 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_off0000e339.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE339 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB50 10716 bytes
SHA-256: 455f1ffc164dd96427f28e76be5d4ab4b3a106761e70630f1d04e45ed3c2a644
font_02_sfnt_off000113b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113B1 20036 bytes
SHA-256: 0ec545d5b161280b5ced218ab79786596fbfd4d68f3e266eb080ea0f6ba95df9