Malicious PDF — malware analysis report

Static analysis result for SHA-256 7fdf942bfea0efee…

MALICIOUS

PDF

93.3 KB Created: 2021-08-01 14:01:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 019706245e6a7a31844e0dbeae11d417 SHA-1: e4ecd57d7e05cb77272ea57184bd55f8c09cb907 SHA-256: 7fdf942bfea0efee2177815b59734f2ef37140ac07ee270abca85c2a988fd3ec
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm on disposable hosting, with numerous URLs pointing to potentially compromised CMS upload directories. The PDF document body was heavily obfuscated and unreadable, suggesting it was designed to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://jungvassar.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/26242627278.pdf
    • http://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/tusopefotedimazar.pdf
    • https://tosto.cl/ckfinder/userfiles/files/bejozakafefos.pdf
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609675c9a49ba---88863009077.pdf
    • http://morebricks.com/ckfinder/userfiles/files/80727016836.pdf
    • http://cyuanmei.com/userfiles/file/gofuzemukenikazuxiposa.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160a59d58cf134---meneso.pdf
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c87164092c---11550274336.pdf
    • http://doanekeyes.com/userfiles/docs/buvapewo.pdf
    • http://musorcentrum.hu/files/article/file/diwudegurakuxuramuri.pdf
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/de14a1fjfcb0vr6l74csmggd0s/23274702453.pdf
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acbb36cff56---jogefalo.pdf
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/d1c239082b2a57385371c1c684de90f6/zukojepabezem.pdf
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/6f223b09c6c787f0bd4266c69d06ab8f/6415073984.pdf
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e5fd3ba1eb---19920439759.pdf
    • https://pasarantogel.com/contents//files/perepuradisolowokilulosa.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae63dbf892---49106788324.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb7672cde03---24246206771.pdf
    • https://dusunceokulu.net/resimler/files/40627485931.pdf
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/843a4c1905279ba4bc42e0474e6f8dbb/padekosaxoruzapidoz.pdf
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/5d990dfd1b268d5e0f025a2d0cf97fc0/86424962543.pdf
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160ce9fc7689a6---pagufugaxibusawipinitufa.pdf
    • http://www.zywawiara.pl/pliki/mekovosu.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/9ipo1ukq1tqdi8mnse7bdar4gf/1092631758.pdf
    • https://apoiotelecom.com/imagens/img_fckeditor/file/61717787904.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=exercice+imparfait+cm1+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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f143.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF143 16792 bytes
font_01_sfnt_off00010955.bin
75ef0de9603294373dac24c0948bbffe90a9848ecac9b2310974f62a3002935f
pdf-font-stream PDF embedded font (sfnt) at offset 0x10955 18012 bytes
font_02_sfnt_off0001367f.bin
f5cb5c931111e1b51703100c0ae08dbb3d3cf2bc1dd07220d0f6608aedab12d9
pdf-font-stream PDF embedded font (sfnt) at offset 0x1367F 10480 bytes
font_03_sfnt_off00014e5d.bin
0c133022d1e9883d2ff7035cf84f1fa0be9cfa0d671266bc5a940283bc0f9855
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E5D 16376 bytes