Malicious PDF — malware analysis report

Static analysis result for SHA-256 40bbeb8b2e752e41…

MALICIOUS

PDF

81.3 KB Created: 2021-09-20 16:45:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3029a78458a8ecbb679468cb75118ecc SHA-1: 4c68259b11a8b3f7d74e3231d2a56c79bd29f559 SHA-256: 40bbeb8b2e752e41c6795c54e1fbbf450fc53b5598420160cf45e1b365683c76
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous URLs pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics indicate an attempt to trick users into downloading further payloads, likely through a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://oniceh.ru/uplcv?utm_term=pdf+reader+software+free+download+for+android+mobile
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/5860251e7718892cee7b2891c875278d/vikotiwijomidegusavopo.pdf
    • http://highlevel.pl/userfiles/file/27381468229.pdf
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/b4cb6afc0bcd415a6e1dffde0f15f2cf/10242800159.pdf
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/161336297a011a---mazexakisumavo.pdf
    • http://tycoonmedical.com/userfiles/file/94666671645.pdf
    • https://samirkumarpaul.com/ckfinder/userfiles/files/lowowiratokixegaku.pdf
    • https://langumeistras.lt/i/File/60390096240.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/161386a0da0d12---24472950150.pdf
    • http://sanxuatbanthinghiem.org/app/webroot/uploads/files/danujidexatepuganafuxamap.pdf
    • http://natur-pet.cz/webpagebuilder/ckfinder/userfiles/files/53062809724.pdf
    • http://vincitydata.com/uploads/ckfinder/files/ridozu.pdf
    • http://csc0898.com/userfiles/file/20210908035638_91ggfk.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/8f4c7d27c3ge84jbv8p71suanc/39246676201.pdf
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/d6199d1f30c14335ec77230dffb74692/sotamariv.pdf
    • http://letresorellebio.it/userfiles/files/zeberufuzepovepelijogoni.pdf
    • http://studioghittigargnano.com/userfiles/files/4936469388.pdf
    • http://zhouzhuanx.com/v15/Upload/file/20219172153397336.pdf
    • http://talleresjpg.es/img/file/zujakuj.pdf
    • https://xo-sound.ru/userfiles/file/sidufimafisadukafivuzurig.pdf
    • https://cingenito.ca/upload/editor/file/zotose.pdf
    • http://studiomistretta.com/userfiles/files/93328532789.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d916.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD916 16792 bytes
font_01_sfnt_off0000f12d.bin
b6295fa34d231d68624cff15238c3e54f90cb93f93548015ba3ec9ccda42eb73
pdf-font-stream PDF embedded font (sfnt) at offset 0xF12D 10740 bytes
font_02_sfnt_off000109e3.bin
642ad676f8d197149e3b66697454f180974cfc82491df1cfb071e4e6295fc127
pdf-font-stream PDF embedded font (sfnt) at offset 0x109E3 17524 bytes