Malicious PDF — malware analysis report

Static analysis result for SHA-256 904b36dec783950c…

MALICIOUS

PDF

95.3 KB Created: 2021-07-16 03:54:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e34ff2fe70095312902dc414884e0411 SHA-1: f6d1a96bceaa3a380063812125ec55ffeb49dbf8 SHA-256: 904b36dec783950cb183a22d28fdb954b20cd1d720f41a4234470da2fc79143b
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites or disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of these links indicates a likely spearphishing attachment delivery vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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 https://duocvinhkim.com/userfiles/file/16173441047.pdf
    • https://www.schroedersales.com/wp-content/plugins/super-forms/uploads/php/files/c69ac2f093f8c4b8df843e00c7766b4e/47422252056.pdf
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090ba1c52e0a---nimitojupapadijiwanerirez.pdf
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/1afd164458a6098b4b583362d25b454b/rokepuf.pdf
    • http://hubbardfamilycircle.com/clients/62940/File/55461763857.pdf
    • http://www.blueoak.fr/image/file/81172692102.pdf
    • http://www.srijonihealinghome.com/fckimages/file/tufonilebokexidesuturupes.pdf
    • http://manavpublicschool.org/manav/userfiles/file/lujaxibudegizo.pdf
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/6bff8b23d1f826a3cdd1978927f910b3/motigogexugisesopeseme.pdf
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071e29705708---97424348689.pdf
    • http://naturallabs.de/userfiles/file/pejenopagevoxawozisapavi.pdf
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/fa28e75ddfb220d28cb3db615bf96548/57109558825.pdf
    • https://gregor-biffiger.ch/userfiles/file/melokakamajevozuvazabow.pdf
    • http://pastoret.it/userfiles/files/9641515978.pdf
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a714b37f14d---gewisinuwuwu.pdf
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/cb2ba3ca644b4da9708f9aa31023c630/bofagepukib.pdf
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/ruunnp3mecn0ah97bftu64bb71/46972665766.pdf
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e312acc8077---46147123904.pdf
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/319503a639b004bae79a59454afba319/widuketigimilariwo.pdf
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/23186346540.pdf
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e2f6c5c9476---vigobubeveresefesik.pdf
    • http://valeneighbors.com/userimages/24737914553.pdf
    • https://mytopics.it/uploads/file/43720394758.pdf
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/0c06c6279cc4c4f9d3a7ad6ee3baa280/kuvumesugizitorase.pdf
    • http://spiregene.com/image/files/20210702_215310.pdf
    • https://debcopharma.com/userfiles/file/depoxewilumadodazejudet.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=appendix+in+a+proposal
    • 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_off00011127.bin
50a093deac6592bc8b69c5283fd618da9b29834152a033f8887def749ddb42b4
pdf-font-stream PDF embedded font (sfnt) at offset 0x11127 17936 bytes
font_01_sfnt_off0001401d.bin
79191baeaa6330c78b563b0e659f5e28ee864c62697dfe14c6e3317ebce69f59
pdf-font-stream PDF embedded font (sfnt) at offset 0x1401D 10372 bytes
font_02_sfnt_off000157ab.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x157AB 16792 bytes