Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5587d6dc79cbaa2…

MALICIOUS

PDF

78.9 KB Created: 2021-06-24 04:32:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 3906753a639087f46b0a7f9b2e0fd593 SHA-1: fedda8357b380d60fb76665b3696f280375276fd SHA-256: a5587d6dc79cbaa2fc309854a494fe436398855efe86b881b3178163749b7790
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it's a link farm on disposable hosting and a lure for password-protected archives. The embedded URLs, while some are marked benign, point to various domains, suggesting an attempt to distribute further malicious content. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, indicating it was likely generated programmatically to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://arcomproltd.com/userfiles/file/xibatapujobetipujuxadewe.pdf In PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160703b3a9c0b2---rexubinuxebovuga.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160913d795c714---94370887047.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/735dta35kl98t4ard9l76gfejg/45510096758.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/30f956a8c7d4e6c3404bb922c60359cb/27196414467.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/fjm3n3t9f76ev3j8jcstn1i69c/vebomovojiwixakupezelux.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16070f92b02d88---wekexugakogoku.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfdaf897984---nosawexopigexedekodazazap.pdfIn PDF document text
    • http://emanuelmlevin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/74864438465.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/ranozobofesokogasebor.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/sofasevozonugasesadalifer.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/jv0g1ai4pbjsas52k0p9fli8db/takurevigi.pdfIn PDF document text
    • http://jiendurancecoaching.com/ckfinder/userfiles/files/31164020638.pdfIn PDF document text
    • http://stphilomenaonline.org/userfiles/file/finonugitirerugip.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=blank+lined+handwriting+paperPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB52 4928 bytes
SHA-256: 7a78ddb88aa6aea9f2aeca92be073fc55c77a2f3bf4591511ed8db1cec69aea0
font_01_sfnt_off0000fc0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0E 10748 bytes
SHA-256: 0f7715f9fb263b5b2ac6c9e5c66f4b21952819e757200bdbd4f0e481c8053015
font_02_sfnt_off000120e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120E8 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c