Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd4b2e97cbc71aea…

MALICIOUS

PDF

78.4 KB Created: 2021-09-19 16:58:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9dacff6996cdee0bdb9fcecf30145a58 SHA-1: 0d62fe4fb302ab709383752c36a180b92ea6586d SHA-256: fd4b2e97cbc71aead5a1483ab0b14157c8e05788f3fa0445c6fc269b97ab1ab0
96 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload storage and disposable hosting, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is not benign. No scripts were extracted, and the document body was unreadable, so the primary indicators are the heuristics and the URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • 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://spiregene.com/image/files/20210908_190759.pdf
    • http://aotwresort.net/ckfinder/userfiles/files/gerejiw.pdf
    • http://bnblspecialities.com/userfiles/files/57473103256.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133e71e0b55e---1469774901.pdf
    • http://bettaletroom.com/file_media/file_image/file/bemegajabujawewunusej.pdf
    • https://pmfegypt.com/userfiles/files/87714984801.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b54859bf2f---76944823933.pdf
    • https://esportenerd.com/app/webroot/ckfinder/userfiles/files/fogadidape.pdf
    • https://dom4m.lv/userfiles/files/xiravawo.pdf
    • http://letsfinal.com/userfiles/file/kujisaduwexuxo.pdf
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/susutekak.pdf
    • http://broadviewlibrary.org/uploaded_bvlib/file/bujotufa.pdf
    • https://ladangmimpi.com/contents/files/felaguzemedo.pdf
    • https://tipresentoio.it/images/file/gojivoduxigad.pdf
    • https://chulintemple.house-well.com/CKEdit/upload/files/71107738834.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1613db24295146---ziwuvetotiworapele.pdf
    • http://jowinbio.com/upload/files/202109061452136937.pdf
    • http://abworder.com/uploads/files/14205147387.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613038b248a17---84980062694.pdf
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/43768291733.pdf
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/3e9peg7ov9t760lc9jab077i93/41703794996.pdf
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/8fdf2118de5374db1a39d47a9fa4c7d0/zetixijagav.pdf
    • http://richmore.kr/uploadfile/fckeditor/file/32006428726.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=imls+download+apk+no+ban
    • 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_off0000ce94.bin
ae5deb4755a26bdaf2e0d71c437bf304db8a34f54741b061c3701cda2ec42469
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE94 10400 bytes
font_01_sfnt_off0000e5df.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5DF 16792 bytes
font_02_sfnt_off0000fdf1.bin
263c2260141f9c356501f82e5317f3a50138cfa5156ad8f1dee6d47a7c8a6521
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDF1 17588 bytes