Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d2fe5134a64d28…

MALICIOUS

PDF

66.2 KB Created: 2021-02-17 17:18:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-06-05
MD5: ac70f0138a107c4f316b44a9a1bcb490 SHA-1: e1e1b46b4c639a6bd1f1a2e1dff5de6103b9cf8c SHA-256: 81d2fe5134a64d28a4baaa4c6ada7916b2dc0b07bb4872bdf30e2b1bc3c3ed29
134 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to S3 buckets with seemingly benign filenames, but also includes a redirector URL (https://maypoin.ru/aws?utm_term=composites+are+used+in+aerospace+industry+because+they) which is flagged as an SEO redirector. The ML classifier also flagged the PDF as malicious. While no scripts were explicitly extracted, the PDF structure and heuristics suggest an attempt to drive traffic to malicious or SEO-farmed content, potentially as a phishing lure or to distribute further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9850

Heuristics 4

  • 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://maypoin.ru/aws?utm_term=composites+are+used+in+aerospace+industry+because+they PDF link annotation
    • http://sungo1.space/82989021827us2qd.pdfIn PDF document text
    • http://org-fruit.space/abellio_corporate_travel_refund_formq834u.pdfIn PDF document text
    • http://vedoluzomo.iblogger.org/fobefunekubuzurepepuno.pdfIn PDF document text
    • http://naderuromopuru.22web.org/beach_buggy_blitz_mod_unlimited_money.pdfIn PDF document text
    • https://torudedo.weebly.com/uploads/1/3/4/3/134352944/nirexi_tajomis_lomesiwepiba_kebuni.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/bufipevuril/justified_imdb_parents_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/zifozujiwi/65593614991.pdfIn PDF document text
    • https://s3.amazonaws.com/sitozi/60563484652.pdfIn PDF document text
    • https://s3.amazonaws.com/minegikukovel/kazakhstan_temir_zholy_annual_report.pdfIn PDF document text
    • https://s3.amazonaws.com/paxunu/diwaxedanapelavepetin.pdfIn PDF document text
    • https://s3.amazonaws.com/liwara/area_of_circle_worksheet_grade_5.pdfIn PDF document text
    • http://kejakum.rf.gd/xevojopikimoduwevonisusu.pdfIn PDF document text
    • https://s3.amazonaws.com/xifabilejilab/buffer_overflow_attack_book.pdfIn PDF document text
    • https://s3.amazonaws.com/sinamozagemoger/100th_day_gumball_machine_template.pdfIn PDF document text
    • http://lekipuvuji.epizy.com/act_practice_test_2008.pdfIn PDF document text
    • https://s3.amazonaws.com/taguxif/jopafavepafosuvexino.pdfIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f6c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C9 5428 bytes
SHA-256: f238a7f1a3bbe7a16b78933ba4a84b730af7ffb8603f7d0325ddcd7adde53a0f