Malicious PDF — malware analysis report

Static analysis result for SHA-256 68a4a5f4bffdf990…

MALICIOUS

PDF

76.4 KB Created: 2021-08-11 15:05:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c5403e93142e83b415a0827fcf0d1f32 SHA-1: 07861f7e9420fafaa45e50ca22f5ef3b1e9a4cde SHA-256: 68a4a5f4bffdf990e391280c547141192c9824d2e91e8975d603dc103c1f3d26
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload storage and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://theelementrama9.com/userfiles/files/10303412603.pdf In PDF document text
    • https://apsco.ly/userfiles/files/boxetota.pdfIn PDF document text
    • https://organicfertilizerproduction.com/d/files/turotorilezebetuzoj.pdfIn PDF document text
    • https://digireg.pl/upload/18556266296.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/20297909111.pdfIn PDF document text
    • http://alituncer.com/userfiles/file/pedatelojazugasuregaw.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16076c4fba801c---juzokilagajoxiginar.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a1318ca920b---tadafi.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/245772fe23f8f25b729aba18a1a9d497/67703935235.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160adecf6e2464---83649932832.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0a2f6f332---galupudasedivi.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087c2f842973---femelonugizirolawabufu.pdfIn PDF document text
    • http://allseasonsart.com/uploads/fck_uploads/file/zabarokowadan.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/62742059877.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b13d0ddad9e---tubufidozet.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f56aec2f5a---53936314613.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fb9cf900d5---totemodekugug.pdfIn PDF document text
    • https://apc-algercentre.dz/ckfinder/userfiles/files/wepufonotatikidezozis.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/646b5b3c891dd9acb09e55be2b0eab29/76268364668.pdfIn PDF document text
    • https://www.treehousecare.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8c16dcf76---fijapikalepukare.pdfIn PDF document text
    • http://copingconversations.com/userfiles/file/34745600113.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/d8k8dp2t632i73ahuv88s50um8/74371484773.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210628_4CCBEF5DB5C31EA5.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/2304adb58ce6bc29ed0e2fd4a91480de/tipavajeku.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/65474025505.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+beat+riddle+school+5+walkthroughPDF 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_off0000c694.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC694 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dea6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEA6 16688 bytes
SHA-256: fa7dead0ab1ba84473c6d6ae198aeabc1488e222dc708f5d385a0e86e6bb1741
font_02_sfnt_off000109bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109BB 11088 bytes
SHA-256: c53e09c571675dca322c265fe69ebc869586d850c7f02eb0ad12467f233d4c58