Malicious PDF — malware analysis report

Static analysis result for SHA-256 3db79cf8f79e11a3…

MALICIOUS

PDF

87.5 KB Created: 2021-07-08 03:22:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f37341adbd98ada6923ed42ba00290ff SHA-1: e85ab29f6d62742b01e4d6b97923ac043807cd7e SHA-256: 3db79cf8f79e11a3a43efb9545d9a03e84a30cb875623410c0f004d0a184511a
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous links pointing to compromised CMS upload storage and disposable hosting, indicating a link farm designed to redirect users to potentially harmful content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a vehicle for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://whalesart.com/uploadfile/file///2021070202052097.pdf
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f48d66c3ff---vabowudomaxagama.pdf
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/m59ldsaek0mt49vchfq2bri4to/pisegokitivirebotofo.pdf
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/344e59685c0e552b86eff9c35e02aa5c/dagikikusifakotimibiz.pdf
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099f96de7be7---18327541073.pdf
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16086b21455746---remorisi.pdf
    • http://steakclubhn.com/campannas/file/fafisoz.pdf
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aca34bef982---47559800851.pdf
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/94dff408fe3eb638cb248e502c0711ec/tovuvadonerarezanis.pdf
    • http://przychodnia-felinskiego.pl/uploads/editor/file/73638304365.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d61ad406819---jivijosuzalenumaw.pdf
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a703018976b---60246267095.pdf
    • http://emyorganizasyon.com/emy/ckfinder/userfiles/files/16759065611.pdf
    • http://xlsferrosilicon.com/d/files/86062374266.pdf
    • http://etasystem.net./userfiles/files/64618896936.pdf
    • http://auchli-appenzeller.ch/userfiles/files/fokavubexejovapur.pdf
    • https://ankaratemizlikcim.com/depo/sayfaresim/file/99410454739.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e0c394eb280---rixitavujadu.pdf
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/58728f43205a2265c6209c194509bef9/xokisejolenafem.pdf
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609271896249f---922458569.pdf
    • https://kanalprofi.at/UserFiles/file/44478840641.pdf
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160987b7f6b39d---8037417563.pdf
    • http://canoto.us/Images_upload/files/30076123611.pdf
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073054dc7608---poxina.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=single+mother+naked
    • 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_off0000f65d.bin
e5ce33c537f666f1fd6ed78b7ca85ed9a3e73ec36f35aa68af9bc613670ffe97
pdf-font-stream PDF embedded font (sfnt) at offset 0xF65D 17048 bytes
font_01_sfnt_off0001221b.bin
8b1074ffecf350e972d4dfb833f1e3b938a0b4c1df172104aea79d29bfd097be
pdf-font-stream PDF embedded font (sfnt) at offset 0x1221B 10696 bytes
font_02_sfnt_off00013a32.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13A32 16792 bytes