Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a636cd67e87151e…

MALICIOUS

PDF

74.7 KB Created: 2021-09-05 17:03:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2a1819bc5e5bd7f94232bbb3482f3cb2 SHA-1: d472e90e1507240b94a43e0a5fa08d80c5c66ac4 SHA-256: 5a636cd67e87151e2673a2e563132ae7a7030000c7beb7bb063238d739c8f6ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links pointing to compromised WordPress sites, indicating it functions as a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://pistant.ru/uplcv?utm_term=solution+manual+of+elementary+linear+algebra+11+edition PDF link annotation
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/1609b0dfbe83ed---36009436462.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16077398eadce2---62324615987.pdfIn PDF document text
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/fef740656e5c2ae90009f3dfcdd259e2/49658752134.pdfIn PDF document text
    • https://destockbaby.com/ckfinder/userfiles/files/nikibezogunoret.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16080543283371---sewudafugivepizavez.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf1046782f---lovixasumomuxiruturati.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160c355f057716---xagaramuxapebuxivoradipak.pdfIn PDF document text
    • http://indigobaby.eu/upload/files/tosis.pdfIn PDF document text
    • http://chixue.com/uploadfile/file/20210718095234.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/3vj3has9h2ccepv4bdisamm1rd/turezasibafusemukikolalu.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/l9g7kj4tvdepg8mq5fa6mrmgpi/gekezoguxo.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210812092035.pdfIn PDF document text
    • http://smart.sut.ac.th/tsme/src/lib/ckfinder/userfiles/files/56448027716.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160829516d2b59---warenumad.pdfIn PDF document text
    • http://kbautotech.com/board/datafiles/imagefile/sexipozinexevutewugapam.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/navavotidexejo.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/39495236400.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/18651356883.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bc1aba430b1---votujijofafegetitipu.pdfIn PDF document text
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca0b6e9025---56202129036.pdfIn PDF document text
    • https://ruh-center.ru/userfiles/file/xiwifiwavokaduzumuw.pdfIn PDF document text
    • http://juha.be/_files/file/43311946147.pdfIn PDF document text
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/4550099500.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/6b410bcb59308ba970b47364e7408ffc/pebib.pdfIn PDF document text
    • http://rockhousemethod.com/ckfinder/userfiles/files/6479445800.pdfIn PDF document text
    • 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_off0000bf8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF8C 17168 bytes
SHA-256: 45ad65d58705ef992c5119dd0243bb70126728c127817c372fa3ba1f7311411b
font_01_sfnt_off0000eb47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB47 11008 bytes
SHA-256: 377b8e17874a6c9ae966cafbf1ccd789457e7c6457ac724fe08c94023ca9ace7
font_02_sfnt_off000104ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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