Malicious PDF — malware analysis report

Static analysis result for SHA-256 44c72b323464875d…

MALICIOUS

PDF

81.2 KB Created: 2021-09-12 21:42:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2ccff12a5d3f4496e1cb9f0dbf751ed2 SHA-1: 5ca820cc159306d2d20c7d88ff433fd8a50546f7 SHA-256: 44c72b323464875d644047cfe13a7f11f1926ade8fbafa64923b94378c58e8e7
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple link farm heuristics supports this assessment. No scripts were extracted, but the overall structure suggests an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://www.de.ruben.pl/ckfinder/userfiles/files/12457429474.pdf
    • http://lesmashclub.com/imgUpload/files/79942805839.pdf
    • http://www.cafeinca.com/img/public/contenido/file/supowabamupaneziwuvatol.pdf
    • https://dubaimotorcycletours.com/uploaded_images/files/49823221054.pdf
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/jb5k2e45hr0cv4j1bcf2l1uri3/nuzubidolesokorufu.pdf
    • http://gpkoaee.ru/ckfinder/userfiles/files/rubibusere.pdf
    • http://ansing.nl/userfiles/file/zubawewakufad.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/16133847d1308a---15296814719.pdf
    • http://enjoyisagenix.com/ckfinder/userfiles/files/pinudobetidugubobaboripa.pdf
    • http://lednotice.com/userData/board/file/36483868878.pdf
    • http://huntland.hu/upload/file/49389852933.pdf
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161395fcd6bad8---migobubimiperasu.pdf
    • http://mosvag.ru/img/lib/file/84327042474.pdf
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/09c804b6d9da0268419601c191d737d6/jelutet.pdf
    • http://ciskmv.com/css/file/45411219267.pdf
    • https://sakura-bashi.com/uploads/files/202109120608276644.pdf
    • https://bywuf.org/upload/editor/files/13345998604.pdf
    • https://poolpoint.be/uploads/file/roviranesujeripibarus.pdf
    • https://krossi.ru/images/content/files/kubojovawo.pdf
    • http://sllight.ru/design/img/upload/file/tifuwoninif.pdf
    • https://avenue102.com/uploads/file/susemetakesuxabiriminufim.pdf
    • https://peoplesmodelinternational.com/ckfinder/userfiles/files/65427539869.pdf
    • https://marblo.com/app/webroot/img/files/61259879886.pdf
    • http://pcccmiennam.com/media/ftp/file/doxuwozubekulawuwenalubej.pdf
    • http://ski-experience-japan.com/images/blog/file/takufaweniwebakez.pdf
    • http://architettoangeli.it/userfiles/files/85278839027.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=audio+mp3+cutter+mix+converter+and+ringtone+maker+for+pc+download
    • 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_off0000d795.bin
0294c52b79a721fe9f07288e66797daf7596f2080934a056202b9be0cecf192b
pdf-font-stream PDF embedded font (sfnt) at offset 0xD795 11392 bytes
font_01_sfnt_off0000f257.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF257 16792 bytes
font_02_sfnt_off00010a69.bin
9682d9e83e84f2e735e8bcb5f32ea37da20569f0486f39b4d6043e789c13f363
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A69 16932 bytes