Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b2751761634fee…

MALICIOUS

PDF

107.8 KB Created: 2021-03-10 19:09:23 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: c623cb1bf221c0bcc151a4c064c73ee6 SHA-1: b4834542679a0090a29ab1a4a9776e65ac3616c6 SHA-256: 81b2751761634fee81c9a49d4d70407352c3020c875b2eb5816bd37a32038f3b
194 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

The PDF contains numerous external links, many of which are SEO-optimized and redirect to a domain associated with phishing. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_UTM_REDIRECTOR_LINK' indicate a deliberate attempt to create a link farm for SEO purposes, likely to disguise malicious links. The primary suspicious URL identified is https://dugedepap.ru/award?keyword=estrategias+de+afrontamiento+del+estres+academico+pdf, which is flagged as unknown reputation and is part of the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9576

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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
  • 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://dugedepap.ru/award?keyword=estrategias+de+afrontamiento+del+estres+academico+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4402956/normal_604016ac3cd3d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415291/normal_5ff53b070466b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://2a082fd4-e93f-4b8e-9e59-408fa046b31c.filesusr.com/ugd/e334dd_e8c999f240d249f4982dcf7db5ab07b2.pdf?index=trueIn PDF document text
    • https://54d25d35-1219-4e5f-97c3-905e72ea606f.filesusr.com/ugd/6d59ab_7675b9819fe64721aafdc7474b5929ab.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/musoxifuvitalo/zilosodiweniwi.pdfIn PDF document text
    • https://9d50af6f-dbf7-41ba-b854-83985329a12b.filesusr.com/ugd/33c377_5f631b3fe092495e81be7ef70aac1310.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/towakog/how_to_replace_toyota_corolla_key_battery.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/804c0498-28a0-4c02-b92e-2fee5ce43604/stanford_university_design_thinking_course.pdfIn PDF document text
    • https://d896c2b7-539c-4146-aa8a-b39d26e096d8.filesusr.com/ugd/a98ecc_58798d1367f44cf197017afee901f5a7.pdf?index=trueIn PDF document text
    • https://994180ce-385f-4272-9833-4a204a825e0f.filesusr.com/ugd/ec0c41_981f984ce4be4ae7b6aaa6a2f0708a21.pdf?index=trueIn PDF document text
    • https://14da0a27-f261-4d4b-8668-3a369f5c966d.filesusr.com/ugd/46429b_0f74d6fbe6ec4f7badd0229fa4cbcbf8.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pazerogasarinu/nodom.pdfIn PDF document text
    • https://aa514bbb-a96e-4bc9-8ff3-0ca2edd1104f.filesusr.com/ugd/3fc21f_473c7dd1ff324f7d86fd6a00c8cdf287.pdf?index=trueIn PDF document text
    • https://c7f0abc7-d23b-482d-bd16-0771495bb668.filesusr.com/ugd/bb13a2_351908d6751d457a9a02f44f82497b87.pdf?index=trueIn PDF document text
    • https://c8070bf9-ed42-4c5d-8eb8-ca35ee70f136.filesusr.com/ugd/d38238_4d332b39952743a1b749a38796bb8d75.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/d13c1607-8394-4101-9839-e3fd35a6d23f/the_masque_of_the_red_death_symbolism_quotes.pdfIn PDF document text
    • https://s3.amazonaws.com/dafumuxitupav/dozakekafupidi.pdfIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000180ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x180EF 5432 bytes
SHA-256: a9e6683f7eb40ec6fdd584fd8f229a1a678e0130a79678318b61cca5ed29b743

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