Malicious PDF — malware analysis report

Static analysis result for SHA-256 98e8e0455236c547…

MALICIOUS

PDF

38.6 KB Created: 2020-08-08 14:25:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e170b0219f18ec6222b5a205ed7fb546 SHA-1: ad113bbdb2c0aeb772785376ac428413fa7c091e SHA-256: 98e8e0455236c547389a398438994680ff3e9d53f3009f14a27bb8f38e98058c
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to external resources. One critical heuristic indicates that the PDF links to known malicious redirector infrastructure. The primary URL identified is a redirector designed to lure users with keywords related to exam papers. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is part of a link farm or SEO poisoning campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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.com/pify?keyword=cambridge+movers+exam+sample+papers+pdf
    • http://files.paulvernoncounselling.com/uploads/1/3/1/6/131606094/reweni.pdf
    • http://files.sawdustsistersbirdhouses.com/uploads/1/3/1/3/131383255/6e8a76.pdf
    • http://files.lanefchocolate.com/uploads/1/3/0/8/130814169/a89ececafbfef6.pdf
    • https://shop.swiss-exams.ch/produkt-kategorie/cambridge-exams/young-learn
    • https://cdn.shopify.com/s/files/1/0428/9599/9129/files/katimobat.pdf
    • https://cdn.shopify.com/s/files/1/0432/4130/8319/files/fezafugetawus.pdf
    • https://cdn.shopify.com/s/files/1/0434/8212/0357/files/acceptance_and_commitment_therapy_overview.pdf
    • https://cdn.shopify.com/s/files/1/0432/7066/8453/files/70168949965.pdf
    • https://cdn.shopify.com/s/files/1/0431/3517/2770/files/xenisujakuderepifedowap.pdf
    • https://cdn.shopify.com/s/files/1/0428/9839/1196/files/puraxubikimibiviguk.pdf
    • https://cdn.shopify.com/s/files/1/0429/8617/6665/files/bhaktamar_stotra_download.pdf
    • https://cdn.shopify.com/s/files/1/0430/6075/6641/files/90735709657.pdf
    • https://cdn.shopify.com/s/files/1/0433/2758/6457/files/tomunovifivuxomiv.pdf
    • https://cdn.shopify.com/s/files/1/0432/1126/0062/files/42723634905.pdf
    • https://cdn.shopify.com/s/files/1/0429/9427/0371/files/challenging_lateral_thinking_puzzles.pdf
    • https://cdn.shopify.com/s/files/1/0432/2010/7424/files/61457642756.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000057e1.bin
d484cdb787085108289354aa27f52b58ef5724c66c0f637194aa67f4e249e81f
pdf-font-stream PDF embedded font (sfnt) at offset 0x57E1 5532 bytes
font_01_sfnt_off00006a98.bin
f0dc1188946a16f165a5c6b3013354a58f8d6c6e84f23054650e9e6a317e42ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x6A98 10288 bytes