Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec87310cb4c6498a…

MALICIOUS

PDF

102.4 KB Created: 2021-06-30 19:58:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3c9ee271148ca81f67ad268a27f6ec9a SHA-1: 581b8e78639f24b056f25810380ffce0d1d988b6 SHA-256: ec87310cb4c6498a7c4d5224d479023b8f9e2004a9eb139bed7441250eb333ae
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress sites, likely intended to lure users into downloading malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing and trojan activity. The document body is unreadable, but the heuristics and URLs confirm a pattern of hosting malicious content on compromised web infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9926

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://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608798fab65a2---dururedose.pdf In PDF document text
    • http://mrpokedb.com/uploads/files/38562711597.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/a342a795fdcc9b1ce7a8c1e20f6f1232/fepokuxulubulo.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce89dadecf---11574921213.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6f8cdf2651---motesuferaxejepu.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/44510404064.pdfIn PDF document text
    • http://harissarantis.com/userfiles/files/11722808945.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/4f589839269739131c19c1220e3d3c7c/dakavorobiliba.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093f6ab48c90---80703373960.pdfIn PDF document text
    • https://mercerapparelss.com/userfiles/files/61800460643.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607223c0aace5---50945405935.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0877c8d38---39648214992.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160903d8cec5d0---kinobi.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16084d1f41a391---wipikarukaze.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/44723119312.pdfIn PDF document text
    • http://goldnumber.info/userfiles/file/kaligoluwelajewob.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/b7fa5eb1a9bd18155e4bda1a53a4d3af/78132607345.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a33e159e24e---magupadijizubido.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/9pkjb8pacr0pm8k6jfc3il3m6p/namoka.pdfIn PDF document text
    • http://duepassidalcentro.it/userfiles/files/goxewum.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/16ccf1fe436e153e518642674326753c/34490464795.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/88108949363.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/kgtpsppu6guquf0m7a2kf3vb07/vudidopexididuniwi.pdfIn PDF document text
    • http://pogservice.ru/userfiles/file/7914275117.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=houses+for+sale+west+islandPDF 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_off00012ee2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EE2 10524 bytes
SHA-256: 09be8861ec0992c22e585aefbaef4e7d7893b470f11b82f6826872b9c0b53210
font_01_sfnt_off000146ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146FF 17364 bytes
SHA-256: 759efe445498b4b9dcf0642a458efbdc474a1b01447bb4585fdd740d8262b20e
font_02_sfnt_off00017440.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17440 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1