Malicious PDF — malware analysis report

Static analysis result for SHA-256 1ac98894eec42173…

MALICIOUS

PDF

96.3 KB Created: 2021-06-05 23:02:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 4b7a1e7469ebbfca569c7501047d2cc1 SHA-1: 1248d1a0aeb12251e915bb3efb5a0408c9341db4 SHA-256: 1ac98894eec421737525f375e23fef5509fcf933eee028812660d23f69277c1b
196 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to SEO-optimized redirectors, indicating a link farm designed to drive traffic to potentially malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://zajinet.ru/123?utm_term=date+format+milliseconds+bash PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4408873/normal_5fcabdda1ce11.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4367273/normal_5ff07234466ab.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4388421/normal_60b320762df42.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465907/normal_601d36e6cb7a6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465690/normal_6021030669224.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4376374/normal_5ff1119515a92.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4484633/normal_60039137018a0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4409413/normal_5fe0be3587cc4.pdfIn PDF document text
    • https://puxefulido.weebly.com/uploads/1/3/1/3/131383426/gufavepizufu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4487201/normal_5fee0ec1aca28.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421943/normal_600a031939d7e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374688/normal_60535dfd85a68.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4374859/normal_60b316fa8c8cd.pdfIn PDF document text
    • https://jazasamiwuri.weebly.com/uploads/1/3/4/8/134889091/d51167c9e686.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369783/normal_60550f86f25ee.pdfIn PDF document text
    • https://gebigimudixerez.weebly.com/uploads/1/3/4/3/134374499/9679705.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/6685e944-d2ed-4e4c-bdc4-6d1c59b8e582/41988201599.pdfIn PDF document text
    • http://redelaw.pbworks.com/w/file/fetch/144652119/principles_of_helicopter_aerodynamics_with_cd_extra.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/39eceb4a-c3c3-4292-a990-4683e6be33f0/how_much_is_autocad_software.pdfIn PDF document text
    • http://vakerul.pbworks.com/f/17118374582.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c1dac43c-1217-48d1-a8bb-5c21793f0408/primera_constitucion_de_mexico_1824.pdfIn PDF document text
    • http://zilebunod.pbworks.com/f/27137088143.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/49fd2436-349f-4567-9c55-27c0e3a2148f/nail_salons_open_near_me_cheap.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6291ed58-e036-4ea8-b716-a89688b5ac36/52397053508.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13544 5400 bytes
SHA-256: 52b8d9140ef62589510df0d625c0ddf38f3955fc6f0d6d4a88d5f08caec0a166
font_01_sfnt_off0001477c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1477C 13000 bytes
SHA-256: 5f95d987b752457328c5988419d8d839b5e9c65eee1904b7ba7f3cb61ae708e8