Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7a281377cb5b408…

MALICIOUS

PDF

42.9 KB Created: 2020-08-19 19:58:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-05-09
MD5: a355f4a002fcf1a4304b43f25cebb2ab SHA-1: 9bb2c326a252728cb26c8c9425de717e142488a8 SHA-256: a7a281377cb5b408da5754d6679bb4fe746ddf3afc7a9a2ed901d67d412f594f
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded links, with one heuristic specifically identifying a link to known malicious redirector infrastructure. Another heuristic indicates a 'link farm' pattern, suggesting the PDF's primary purpose is to host a large number of external links. The ML classifier strongly supports the malicious verdict. The document body is heavily obfuscated and contains remnants of the authoring application, but the presence of the malicious redirector URL is the most significant indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ttraff.ru/pify?keyword=barkhans+are+landforms+of In PDF document text
    • http://jidereje.oberlinsfc.com/uploads/1/3/0/7/130738524/54bcd6b58b.pdfIn PDF document text
    • http://zovom.ttvapor.com/uploads/1/3/1/4/131453870/45d2c793.pdfIn PDF document text
    • http://files.maplevalleysugarworks.com/uploads/1/3/1/8/131871919/24d5f.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/8025/3593/files/big_poppa_sample.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/8013/9423/files/emphatic_stress_in_english.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/3910/4917/files/computer_literacy_test.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/2539/2035/files/adjectives_and_prepositions_worksheets.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/5348/2137/files/fomeridexebujode.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/1384/8731/files/28702171978.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0438/8107/0747/files/arduino_software_development.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0438/6121/3344/files/1020091471.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0436/3960/3360/files/26298566231.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/7839/3749/files/vedic_astrology_books_download.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/6387/7537/files/sepumaxen.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
🗂 Part of campaign: oberlinsfc.com 5 samples

Related samples 3

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

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000068d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x68D1 5260 bytes
SHA-256: 1c3af969332fb34fa09747178c70808c63d19f4382667868a6e95b16162c1bf3
font_01_sfnt_off00007a7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7A7D 10532 bytes
SHA-256: 204eb6e9b20ab22cb9f775aff57f7ade9c1f571c1ce8d8ea7d3550716c518815

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