Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a77a219cb528a73…

MALICIOUS

PDF

42.9 KB Created: 2020-08-30 09:18:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-05-07
MD5: 20448a8b527288648f37812d16587919 SHA-1: ac00b74c3539a534bc021980b72c0f85c6fab45d SHA-256: 8a77a219cb528a737e34b4552d304cbb0b081ffb91a5da1938e24793f809bb8c
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a link to a known malicious redirector, disguised as an English grammar test. The ML classifier strongly indicates maliciousness. The document body, though heavily obfuscated, contains the malicious URL and numerous benign-looking URLs, likely part of a link farm to improve search engine ranking and obscure the malicious destination. No scripts were extracted from this sample.

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.cc/wix?keyword=english+grammar+test+intermediate In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://static.usrfiles.com/ugd/5d2cf3_a125b8e627b44ddc901d19c9a1da564e.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_7f6ba444c7db4b49a039b5a1b5b8059a.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/834936_003d424d5a8841ccb75ec666f238f54e.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_a2c4bba5127a4c2b93fd32c817457492.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/c63dba_564bcbffce054b3493527de913e26c8d.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/0459/1271/files/32819373922.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/9000/9502/files/35794512227.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/5279/2982/files/foguzagejunibu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0437/8663/3374/files/dedomiruxadajosop.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/7035/7661/files/fifikijurotekotapamus.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_4a43290e0ff74657842655e5bd14445d.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_5714bae28ead4cc998467ce501fe75ef.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/585b1d_34d29ced5ea34b5a870a04316e396dac.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/79cb75_f7dbacfbe79d4a25a4f64f6c9cf32d79.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/0779a3_8a64a20c14134143b2468e40f4481bd4.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Related samples 8

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

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005343.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5343 5196 bytes
SHA-256: 8fe706b201b6d14351e4a8cbbe64150121c98b5227433f7973eb0cdae437b73a
font_01_sfnt_off000064b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x64B8 10288 bytes
SHA-256: 8baa83674e5a3eca0770b515363c10c9c0f3e0f0e5541b6ebcd40554f626a323
font_02_sfnt_off0000881e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x881E 16508 bytes
SHA-256: bf0029f2f65a8d03fc5bc6dac3f89872448ee76276b38fcd79a4881ba082e330

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