Malicious PDF — malware analysis report

Static analysis result for SHA-256 f105c354099e3dca…

MALICIOUS

PDF

98.7 KB Created: 2021-06-29 03:45:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 14166a882ad0f8e5075740e2b0eaf6dd SHA-1: e55e16db51d746d5e6083e6d6780a732c3bc7aef SHA-256: f105c354099e3dca7e280607f86e17d24e3ce21767afaa2645691eed6f0af8f9
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and a link farm pointing to compromised WordPress upload directories, indicating an attempt to distribute further malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The document body is heavily obfuscated and unreadable, but the presence of embedded JS and the link farm heuristics are sufficient to infer a malicious distribution pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160740f39c7b16---pedozususiwegovuku.pdf
    • http://bnblspecialities.com/userfiles/files/26050345383.pdf
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/15cf2d5890c767c4d1d21f25cd792e89/80123940940.pdf
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9b3b69ecd7---koxokudif.pdf
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c85f89c048f---jerexiwazowagasajusizof.pdf
    • https://ascinfratech.com/clientprojects/trading/file/37249068710.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a0417303413---30533589751.pdf
    • http://mcleod-bobbitt.com/clients/64742/File/62876630303.pdf
    • http://prattsofdouds.com/clients/d/d8/d85aab9f4bcbae69c8358f7a9990a0b1/File/siniwejefava.pdf
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/d64b7665e9035adfeebb7cdf90025547/92176473423.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160853d38eabea---petokawiduloluru.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/160a80a73e42ce---mipezarirokobuwatetozureg.pdf
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/be5114f67014a431f1d39a88ad5ef6f8/4712823396.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/160bede9c533f5---14102002537.pdf
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/aa8c0baddd1ffbb2bc506a4b3af885a2/16324938296.pdf
    • https://hogies.com/includes/template/uploads/file/wufixejurefuraxifon.pdf
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/e7qf8f2bv9rjarmnnbhg94r4br/99552308112.pdf
    • http://portalcom-b2b.es/img/user///file/_0250267001619918101.pdf
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d1aa47f722---kebunuxosupevokofunevik.pdf
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160abf26b9ee98---63164708807.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073d0f88b1a8---gudogomova.pdf
    • http://tdvvietnam.vn/webroot/img/files/motesosubupobomox.pdf
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a408ad9561---16083671605.pdf
    • http://mundori.com/js/ckfinder/userfiles/files/59725219232.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=examples+of+formal+emails+in+english
    • 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_off0001205d.bin
efb84d309980159ec7b5ceee39340b52fd7b03b9877da6ffd6555cf03faeccb7
pdf-font-stream PDF embedded font (sfnt) at offset 0x1205D 17032 bytes
font_01_sfnt_off00014cce.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14CCE 16792 bytes
font_02_sfnt_off000164e5.bin
978a8a20b920a789baafdc33847b43a592ed58e8db2e07b58144c61282256354
pdf-font-stream PDF embedded font (sfnt) at offset 0x164E5 10792 bytes