Malicious PDF — malware analysis report

Static analysis result for SHA-256 335561b7f4458c72…

MALICIOUS

PDF

83.9 KB Created: 2021-07-13 19:07:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0ebfd72d3a3a47145c1f392443c31763 SHA-1: 89fe6fec965999dade1642ed47559ff1c6c996b0 SHA-256: 335561b7f4458c722df50352b3f43fc8633f6b416cfb29daf5bfbda9ed0456c1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code or redirecting users. Additionally, numerous URLs were extracted, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to distribute malware or host phishing content. The ClamAV detection and ML classifier further support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • 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 http://learnersdigest.org/userfiles/file/rirududifezikobuxalaz.pdf
    • https://topupdana.com/contents//files/24997410552.pdf
    • http://www.rotudavid.com/ckfinder/userfiles/files/wofum.pdf
    • http://seamacros.com/upload/file/xajawejamurawegipike.pdf
    • http://china-hold.com/UploadFile/file/20210512210309002.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/646a56395bd158a8facbc848ec6d6820/zowuzuzomaseloda.pdf
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e37d67b8694---48855893975.pdf
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096c82bedd01---rirugufilepizinug.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c14a38ea747---21178644407.pdf
    • http://apsara.ru/userfiles/file/88065475344.pdf
    • https://ottenburger.com/userfiles/file/kikuxesorogiwuw.pdf
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d23bae95cb---vebenoguzufesik.pdf
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/0e9454abc4442de08080168bf66d0c34/tulometiraxe.pdf
    • https://cedarcreeksauce.com/wp-content/plugins/super-forms/uploads/php/files/65314adbcc8bb26f7d3b5ab26439ee10/belozavuzoju.pdf
    • https://avonsteel.com/UserFiles/file/puxevususoja.pdf
    • http://geredekombiservisi.com/userfiles/file/togafibomis.pdf
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/blkrprtaii2meol7b1bv52i5i3/24056614141.pdf
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/0d78a312d7c824a985bcf7f3396caf2e/newabupuvitedumem.pdf
    • http://robalton.es/Albums/images/file///4326247649.pdf
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/c6j7g0tgpshlop2f5abo8c6bi6/giposezataverifewilukilev.pdf
    • http://battlegrouponline.com/app/webroot/js/ckfinder/userfiles/files/vejajefosodepajofugus.pdf
    • http://yfatc.com/userfiles/file/tomoxil.pdf
    • http://falerisztika.hu/tmp/sojakox.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=cambridge+english+ielts+trainer+six+practice+tests+with+answers+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_off0000db05.bin
bc91e78d09da1150a6a2fced68aeadba7da33314636b2ca0dfe8db945898d045
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB05 19972 bytes
font_01_sfnt_off00010fb4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB4 16792 bytes
font_02_sfnt_off000127cb.bin
a7349b69aa435e2097f3aab02792946ee7b07ab359fe73774fae43431ba3a87c
pdf-font-stream PDF embedded font (sfnt) at offset 0x127CB 11304 bytes