Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b909e454b45b822…

MALICIOUS

PDF

83.2 KB Created: 2021-09-07 18:14:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 772e3e63b546d51042e519fe4bb2cd88 SHA-1: 0b81aad98dc0f16fb9ce38a7041b66acc55ffe64 SHA-256: 8b909e454b45b8223458e087f9cd4c9654a65c200bb3035c1548ae96d206b540
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript and a significant number of external links. Several heuristics indicate that these links form a link farm, with some pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to redirect users to malicious content. The ML classifier and ClamAV detection strongly support its malicious nature, likely as a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://boracayg.com/FileData/ckfinder/files/20210804_C88A4AE824D897EF.pdf In PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/f4sdjoi6rh3suvuq585j7nui7v/8534423233.pdfIn PDF document text
    • https://ms02bet.net/contents//files/27164917605.pdfIn PDF document text
    • http://kancelaria-perfect.pl/app/webroot/media/files/zolevulana.pdfIn PDF document text
    • http://zeguvietnam.com/uploads/ckfinder/files/63927688090.pdfIn PDF document text
    • https://cfbadalona.net/ckdata/files/5012870177.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/918de5200bab770e16a511daf0f51af3/78826088152.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c06becddcb0---72403552451.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/52627122312.pdfIn PDF document text
    • http://wu-pao.com/upfiles/editor/files/vubalavadagemesitelu.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/uleboavjj24r7k2vq03durnvjj/78578024296.pdfIn PDF document text
    • https://verner.lt/images/files/sezopilibatorugemadasa.pdfIn PDF document text
    • http://kyanite.tv/userfiles/file/menuvesuvagowamipeke.pdfIn PDF document text
    • https://art-eria.pl/mandarynka/pliki/files/xutefadetajo.pdfIn PDF document text
    • https://jakspravnenapsa.cz/userfiles/file/88211774524.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/161120146c8823---1264159848.pdfIn PDF document text
    • http://chinalabware.net/d/files/gurapati.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/10549663317.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/gularazedev.pdfIn PDF document text
    • http://w3-japan.com/js/upload/files/beradalegaduwexori.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160819e0ee9992---pixekutusidel.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/7e4df5309c37a6b5a6ad4a3d2b8192a3/46673289223.pdfIn PDF document text
    • http://www.ocptecnology.com/admin/uploaded/fck/file/kuzifidenukimabijunitev.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/93323058442.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=nuwave+precision+induction+cooktop+gold+manualPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC81 11176 bytes
SHA-256: 695339f042a9327bde504d8d59f10016e2b849cc718fe17006c651556892b584
font_01_sfnt_off0000f680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF680 18400 bytes
SHA-256: 787b71c7bd09a161cbb274db99be489c761b5434144eea70956f14dfd93ca492
font_02_sfnt_off00012676.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12676 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1