Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dff1a763e4091f4…

MALICIOUS

PDF

69.8 KB Created: 2021-09-25 14:56:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 34e4462f50678408fd16b5821af531aa SHA-1: 289063385ecdd6e04b04b459abf4b56e24bcc4c9 SHA-256: 4dff1a763e4091f48432fb9d67fd954229a4ed6c5e54eff3b611a44bce9654d6
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified the PDF as a link farm pointing to compromised WordPress upload storage and disposable hosting, with one URL containing a 'utm_term' parameter suggesting a phishing lure. The document body was unreadable, but the overall structure and URL analysis strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://smidgel.ru/uplcv?utm_term=joi+unlimited+coins
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140c3e39dfdb---kagegajuposoxak.pdf
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16149e9dc7607f---ralofibupeferedireporu.pdf
    • http://gemtown88.com/PicOther/file/84718560058.pdf
    • http://www.extramas.com/userfiles/files/9635738607.pdf
    • http://studioturina.com/userfiles/files/12675402997.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613e2e7c1229b---mavubanibasama.pdf
    • http://elcolono.net/userfiles/files/suruzegamoji.pdf
    • http://ongxoanhdpe.vn/upload/files/nilenami.pdf
    • https://andrejc.si/files/file/faluru.pdf
    • https://fultoys.com/userfiles/32603680380.pdf
    • http://transgusto.ch/userfiles/file/33900863196.pdf
    • http://floral-design-lindgens.de/userfiles/file/mimavuluw.pdf
    • http://thedewakohchang.com/image/upload/File/omowabuzunokuvuzopanonaw.pdf
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614e953ad8ee2---25604959477.pdf
    • http://mcutech.net/files/womubavowot.pdf
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/4777b74e8ab072288e1d509e6297aea9/vefogolulemujudi.pdf
    • http://phongkhamthienhoa.org/images/files/zewufofutefi.pdf
    • http://bananamusic.tw/uploads/files/202109140046507417.pdf
    • https://podimercrm.com/img/files/nopenuxaxitedisiliraw.pdf
    • http://hotelalbicia.com/userfiles/file/47964173205.pdf
    • https://mimpi1pusat.com/contents/files/38848952047.pdf
    • http://www.deco-interieure.com/userfiles/file/temilelisanoparavekobuxas.pdf
    • http://kaiyudachem.com/filespath/files/20210911122450.pdf
    • https://burgaseguros.com/userfiles/file/60628323813.pdf
    • https://communeouchamps.fr/userfiles/file/67978455289.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_off0000b20e.bin
bf9fe9e73e10f0c725744f6f7b19e90c8e37e404defe93f17c15d071a4d929e3
pdf-font-stream PDF embedded font (sfnt) at offset 0xB20E 16080 bytes
font_01_sfnt_off0000dab4.bin
fbd48095db292d83a989316df351276304f6576d58d8872dd59ccb876841bdf5
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAB4 10360 bytes
font_02_sfnt_off0000f217.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF217 16792 bytes