Malicious PDF — malware analysis report

Static analysis result for SHA-256 d43fb8a64db2d107…

MALICIOUS

PDF

90.4 KB Created: 2021-08-29 19:06:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9b8f862b010b8ec510362d191e9f7cc7 SHA-1: 24a6c4b57f62cd71cf22f7ecee8e11ed7cd6c796 SHA-256: d43fb8a64db2d107c499993bfca6bc91b21084b11be7a0c848d2fcbbb9da7d49
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, including one that impersonates a shared mailbox auto-reply. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to download a second-stage payload. The presence of embedded JavaScript suggests it is used to facilitate the malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 8

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://chcial.ru/uplcv?utm_term=shared+mailbox+auto+reply
    • https://nguoixunghekiev.vn/userfiles/file/wilurarenuwipoge.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16112e07f9a93e---miritonenalerugarulax.pdf
    • http://5mal4.de/moneyvidya/web/images/userfiles/file/bukasedojet.pdf
    • https://chinatupai.com/web/js/ckfinder/userfiles/files/dibeserudosovi.pdf
    • http://ndt-ultratech.com/files/zetorafezera.pdf
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088e516cebdb---98486106831.pdf
    • http://alrabbancapital.com/file/files/41346721047.pdf
    • https://ost-fogging.com/upload/files/lesoliwuvetezigexef.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/l7q0nlu99m7e4ode34o7e6l1jk/59795078030.pdf
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b0b76273e69---xixiwenifivax.pdf
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608b9980d75bd---66345504162.pdf
    • http://knshzj.com/CKEdit/upload/files/varupudomujobixerifa.pdf
    • https://espiber.cl/images/uploadedimages/file/rizunode.pdf
    • https://mlmrockstars.com/ckfinder/userfiles/files/tuxukinaxekib.pdf
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16094471192e7d---74204352606.pdf
    • http://samilove-payitforward.com/clients/f/f9/f9b0b202ed5d2cb263a89f8a9bd08a94/File/kaboraruvadolugibit.pdf
    • http://britishcytology.org.uk/ckfinder/userfiles/files/83530647181.pdf
    • https://beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/d930007e484fc33421b589542a61b4bc/bakifubofat.pdf
    • http://cbestdesign.com/ckfinder/images_store/files/dinogafofubuvajedarateza.pdf
    • http://takeacode.net/user/d41d8cd98f00b204e9800998ecf8427e/file/vowisevazodubuwuf.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/e7r23m2rae6qmd01k7qbhmvqog/dasaw.pdf
    • http://rinsacars.com/files/others/tikilijejabadazajimix.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_off0000f936.bin
7c7ac13328a88ddd0a1c1518e0e78620be45e5278d27f99521c5680c50f336ad
pdf-font-stream PDF embedded font (sfnt) at offset 0xF936 10916 bytes
font_01_sfnt_off00011246.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11246 16792 bytes
font_02_sfnt_off00012a58.bin
27f120d57c4683bab643e4dae967089aab79e3af51708e4594c6efa08eef8b5d
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A58 18880 bytes