Malicious PDF — malware analysis report

Static analysis result for SHA-256 28a74dd825f5165a…

MALICIOUS

PDF

81.2 KB Created: 2021-06-09 08:43:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: c20c5b0157fb52d5129eb5792fc08e4a SHA-1: b6fcafbcd2b58dc3ad9e2a529a127e1c5c470b91 SHA-256: 28a74dd825f5165a21e7d7d5983ea63798142e954776fd65703f8b599d78bef3
156 Risk Score

Malware Insights

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

The PDF document is classified as malicious by ML and ClamAV, and exhibits characteristics of a link farm hosted on compromised or disposable domains. The document body, though heavily obfuscated, suggests a lure related to 'Genki 1 textbook answer key', likely to entice users to click on the numerous embedded URLs. No scripts were extracted, but the heuristic firings strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://synerhu.ru/uplcv?utm_term=genki+1+textbook+answer+key PDF link annotation
    • http://eko-inwest.eu/upload/file/mupivamivebupefuz.pdfIn PDF document text
    • http://cocoal.com/uploads/file/15791780764.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070aa1f3e379---gezodidixitajovo.pdfIn PDF document text
    • http://gagutp.com/sa_upload/userfiles/file/20210514044515.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ab67a779c2c---foketozonujepibabe.pdfIn PDF document text
    • http://bioscipublisher.com/files/upfiles/file/78058874409.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/43867617406.pdfIn PDF document text
    • http://hani-bee.com/userfiles/files/22760531297.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/fc71ce051a852259198ae76e44953f4d/67552608698.pdfIn PDF document text
    • http://udmvdpo.ru/images/files/39417395354.pdfIn PDF document text
    • https://almondzwealth.com/administrator/imagetemp/file/togepeferijazezuduwipoxeb.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/fb256b7696bf9458723e5f1264875206/sajulewotifitaxub.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/4fea8a0c73427fb0eb53d037505b2772/41369214427.pdfIn PDF document text
    • https://www.northwoodmedical.ca/wp-content/plugins/super-forms/uploads/php/files/do1pcjh83n1seh8k7b55qnjkv9/nevadagodedimolul.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/eb133777c63154fcee53fc3073cf5bc9/94796895377.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/93b54e9bc303ce0bd6b79c9935824fff/vaviv.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609afd29eb1d6---davudegezugazegalagus.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d451.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD451 5876 bytes
SHA-256: 59341695b3fe5d0afa5a9b69029b1bd66c65f2e2e05b23975dd5720e407f59e5
font_01_sfnt_off0000e89c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE89C 5196 bytes
SHA-256: 42c7c9371713cd0f02a0b1db8e14b51906841582952c8ddaefb26d0bc8b338ac
font_02_sfnt_off0000fa7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA7F 10936 bytes
SHA-256: 7c61b98ce9339c0f5ecbb13855c6d3a78b85c80fbd3f4f5dee1b1bf18f7e8b62
font_03_sfnt_off00012052.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12052 16084 bytes
SHA-256: 29b8095464fa9501f2379a4c43ca3ba1b1df604f87f2abcbe11fa9bdafb8ec10

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