Malicious PDF — malware analysis report

Static analysis result for SHA-256 d20a9f8136782dac…

MALICIOUS

PDF

93.5 KB Created: 2021-08-05 04:58:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ca611198a242c0bbdffd0001a597dfdf SHA-1: cbb905813689991ebfa10dd94cf11c607ea4a408 SHA-256: d20a9f8136782dac62af73891b59fc74fc4615c6c3aa6415d86763e0a8bea394
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting it functions as a link farm to distribute further malicious content or phish users. The presence of PDF-specific heuristics like PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://allytemp.ru/uplcv?utm_term=how+to+replace+sram+brake+lever PDF link annotation
    • http://bradhelferlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bowulezadudogitog.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8cd9b5b78---79282566968.pdfIn PDF document text
    • http://lateonsettay-sachs.org/userfiles/file/pizepovoxagejuvone.pdfIn PDF document text
    • http://feynburg-uhren.de/uploads/sanegogobolegema.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/jojemasafivevib.pdfIn PDF document text
    • http://patp1ryb.ru/media/file/rofikikatubolepedoti.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082a17285ce9---jetemanaxizej.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/4f07a0ddacfdca0a1f2f0af1574bef24/kepefevupunudojidilopodi.pdfIn PDF document text
    • http://kubkao-kubpla.com/userfiles/files/53318927589.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff2f7342ca---kutidamujobulupul.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/ac83a0bb67e106737ba9eead7ce4de20/92495538966.pdfIn PDF document text
    • http://fonnepal.org/userfiles/file/penuvijexizudewedosa.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16084dca996c5b---riganimagonusuxesaku.pdfIn PDF document text
    • https://europartner2.pl/uploads/8691764355.pdfIn PDF document text
    • http://ciaooo.ru/uploades/userfiles/file/9625650428.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/c9a4b9313d24c994f4094a38a134e555/folozu.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/hj1r0kr3dfc6qh0906td7b6n9o/41392652421.pdfIn PDF document text
    • http://thanuyentea.com/ckfinder/userfiles/files/59153060276.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/rufuniwawuku.pdfIn PDF document text
    • http://morethancars.nl/uploads/edytor/file/37039452760.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cb380235a05---9733077582.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609d7ae63f7ab---58362679120.pdfIn PDF document text
    • https://easresidence.ro/app/webroot/files/userfiles/files/paduwuxopabifosidepaxakiw.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_off000109c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000121d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D8 10712 bytes
SHA-256: 77aa5286a7ca062bb5844dcecfd7444a8332272f4baf58b43b3ba1c6cf41bd94
font_02_sfnt_off00013a53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A53 17112 bytes
SHA-256: 76449a94c7a853b2612ac2369b65ab5d99c2896e4eaa69be1bd86df701640a9e