Malicious PDF — malware analysis report

Static analysis result for SHA-256 c891e8517354a5e1…

MALICIOUS

PDF

88.3 KB Created: 2021-07-25 21:32:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ba01f82bd43f808f314e04a63d718c31 SHA-1: 4f88ba347d5f65f0cfc9a521617db3b4615bf0e6 SHA-256: c891e8517354a5e1976b9389ca64e46a6d4374a892b8139b1846901d1140ca2e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' reinforces this assessment. No scripts were extracted, but the overall structure points to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://kangaroovietuc.vn/webroot/img/files/90634161403.pdf
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2016aa2600---87267605559.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5ad5ab5fb---jagose.pdf
    • https://alllegaltask.com/wp-content/plugins/super-forms/uploads/php/files/85u57jn00p5hqtq7js4pfiiagv/vugexesokapefefo.pdf
    • http://bjallstar.com/upload/file/zepukimutipageforurame.pdf
    • http://webinaris.org/ckfinder/userfiles/publics/files/danonen.pdf
    • http://parilka.by/var/upload/file/polikubimufinija.pdf
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/bdokmdelhl2s1h9sokfbdndn83/47359942606.pdf
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086f98a1c2c3---82014568808.pdf
    • http://kasargod.net/uploads/file/vololi.pdf
    • https://deltagroup.bg/uploads/file/galozemilesedevusikape.pdf
    • http://oaklandscreche.ie/userfiles/files/wiferitolug.pdf
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/a243c84de20bbe5dee2ef0c96d983718/74839055465.pdf
    • http://hoadondientu-ptp.vn/images/ckeditor/files/rawod.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b94148c84---napefevapewivexizes.pdf
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e3fd1e61fa2---56856960789.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/d697e97317ce0b55a8132888c53e297f/15928191820.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c934e1aa618---74338953480.pdf
    • http://ledins.lv/cms/file/kifanoridaresezeline.pdf
    • http://gesundezellen.de/neu/userfiles/file/lajali.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1609b0eba79ab4---xesudibasagaxanomozosagak.pdf
    • https://tradingphrases.com/userfiles/files/nomujerezitim.pdf
    • http://kadh.kr/bobod/upload/file/binikigubewemaf.pdf
    • https://baigiangtoanhoc.com/upload/files/83804584334.pdf
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bf47c17e6a6---87083910597.pdf
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba34355e16---61339356325.pdf
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc8e257cf3---47177852142.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=tavistock+soft+close+toilet+seat+fitting+instructions
    • 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_off0000f463.bin
9df81284651f1892f9bf56c1f3e984bb53f5f21729f8c66be086a8372387d6d0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF463 10732 bytes
font_01_sfnt_off00010d48.bin
0fd5117cc1aec39f8e4bcbed717ebca006bdc319d9212dbbb41cf5c238cec3a8
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D48 17220 bytes
font_02_sfnt_off00013a32.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13A32 16792 bytes