Malicious PDF — malware analysis report

Static analysis result for SHA-256 c88eff6ed0f81a5d…

MALICIOUS

PDF

103.8 KB Created: 2021-07-22 02:10:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d69a23c2770cfba4eeae8b7f3f66c55b SHA-1: 70ec2adcbf48c05ad3a2ec012c978eee65646cf6 SHA-256: c88eff6ed0f81a5d81aa6704ef1f96b94af6ec31cf13e7e493be7ea9039e2a1d
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The embedded URLs and the nature of the heuristics suggest an attempt to lure users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://ahchala.com/img/file/pepej.pdf
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1609431c1364b6---gowamekafibefonu.pdf
    • http://cooper1972.com/clients/b/b4/b451ebb09e7e0345645526f893d9a49e/File/94825139183.pdf
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16078eefa7674e---mebokixodu.pdf
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/ab974623d0be26eac50eab31dc3ff85a/21009036042.pdf
    • http://zxpgw.com/userfiles/file/35252256817.pdf
    • https://sunarchegypt.com/userfiles/file/14899897318.pdf
    • http://2sisaccount.com/userfiles/files/62143702581.pdf
    • http://northcity.rs/slike/files/xupawobefoxan.pdf
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160bb77beb254d---remifuguforesarezane.pdf
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/42dc568699630d91193bbecc0da78cf3/lirapetivijupimokanu.pdf
    • http://agendatourvietnam.com/hinhanh/file/kisiris.pdf
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c2bba530bc---diviwotejuvu.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dc111ac14c5---77311762668.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088b9c4cf42e---jukesotatixinedog.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/020d5ccaf27af08de9a4c5778d8c15fe/jiwosikutozukibeda.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/bad50d3776872f56dc47a58fb70f7e99/tewaropoged.pdf
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/4d03b30a77e948257003ca2b01b5b6a1/ropabisad.pdf
    • http://lroundup.com/clients/d/d7/d7466da0ad72d96b64793f89c518a0d9/File/lalitavujojobe.pdf
    • http://tortsurprise.ru/upload/redactor/files/92383070900.pdf
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/55598968998.pdf
    • http://ehhs1969.com/clients/6/67/67a0fa02f482ea8575b7cec7429e43a8/File/64412649179.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=provocative+therapy+frank+farrelly+pdf
    • 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_off000130b9.bin
d864b41916f15d897a040f15ec72d938a2fe55006347dc97e13397b12a8878e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x130B9 17664 bytes
font_01_sfnt_off00015edf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15EDF 16792 bytes
font_02_sfnt_off000176f6.bin
e6c769279a680f703bf496220bfc2a2f34d166745570f973be1a4cc5d6ae23cb
pdf-font-stream PDF embedded font (sfnt) at offset 0x176F6 10820 bytes