Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2b39630b1bf3b17…

MALICIOUS

PDF

73.2 KB Created: 2021-09-19 00:21:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 80f68215606687ed7a8305de5d9f39ba SHA-1: 3b16408e29590bbf7fc59730cd6a99d03a39ca85 SHA-256: b2b39630b1bf3b1745aaf4bc8526c3afd90b96277c2a28374bfbe53ecb5f00d9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript and numerous URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=snaptube+apk+down
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/620d345f0b850be5ae7f6504e5b4b290/kukelevaredev.pdf
    • http://alliance-ic.ru/uploads/file/43226692012.pdf
    • https://nocenzura.space/web/img/podborky/files/23976214925.pdf
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7df9ac3a8---16077837220.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/16146537c00d69---71841506991.pdf
    • http://topoint.cc/userfiles/fckFile/20210914120441.pdf
    • https://larustt.com/upload/ckfinder/files/88119230041.pdf
    • http://ecolservizinettuno.com/userfiles/files/88181369012.pdf
    • http://dlastudenta.org/Upload/file/11709928435.pdf
    • http://dezis.ru/uploads/files/52531183221.pdf
    • http://taiwangallant.com/uploads/files/202109072027498144.pdf
    • https://isleo.com/i_photos/file/batazilotemanujojir.pdf
    • http://jamesandsons.ca/userfiles/file/fagosiwusidewefamija.pdf
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142514046e9b---zagolegudotadalunin.pdf
    • http://soloparamideco.com/js/new/fckeditor/userfiles/file/fasufekituba.pdf
    • https://aynadakikemalizm.com/resimler/files/fubexamager.pdf
    • http://studiomistretta.com/userfiles/files/91707750236.pdf
    • http://gpp300.fr/userfiles/file/natamolikefuvalukirasesi.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16144a10774994---vuxoga.pdf
    • http://flyingkirin.com/uploadfiles/file/161022496313.pdf
    • https://alstar.uz/images/shared/file/73866945037.pdf
    • http://apartament-krokus.pl/userfiles/file/ribiragidamewemep.pdf
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d5d8bec346---64897430817.pdf
    • https://helices-evra.com/userfiles/file/zipatiniwaximeno.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_off0000be0d.bin
087fd908b7bc7866b4bda00b9bdcbe98225cb7c2f14aaacfbdc9086279171d4d
pdf-font-stream PDF embedded font (sfnt) at offset 0xBE0D 10472 bytes
font_01_sfnt_off0000d5d5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D5 16792 bytes
font_02_sfnt_off0000ede7.bin
1116ffb6230a3b91afd2aeb3df32e5d8f26c95c7dded03f8a93d581de594a77a
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE7 16172 bytes