Malicious PDF — malware analysis report

Static analysis result for SHA-256 87ed0aa71d8f9369…

MALICIOUS

PDF

40.2 KB Created: 2020-08-10 21:32:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f94753eca2397d262f8ce43fa6c3c8a5 SHA-1: 7718c1fb0491ef25fa8bef929c813793b4d4ef8a SHA-256: 87ed0aa71d8f93696b09d6d3d1734a64bc18e206d267a3e7b6f1fd8067b1d460
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating a link to a known malicious redirector. The document body, though heavily obfuscated, contains the URL that leads to this redirector. The presence of a large number of external links, many pointing to Shopify, suggests a link farm or SEO poisoning tactic to increase visibility of the malicious content. The ML classifier also strongly flagged this PDF as malicious.

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=data+structures+and+algorithms+online+pdf
    • http://dasapidun.thedillybag.net/uploads/1/3/2/8/132816202/3f4e5.pdf
    • http://lurun.usaqingshan.com/uploads/1/3/1/3/131380600/1a3f6a01c.pdf
    • http://vesiga.anniesullivanband.com/uploads/1/3/1/8/131871740/58bf96355ebc.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/60233972239.pdf
    • https://cdn.shopify.com/s/files/1/0448/0558/7106/files/pneumonia_adalah.pdf
    • https://cdn.shopify.com/s/files/1/0433/3066/6651/files/23442586721.pdf
    • https://cdn.shopify.com/s/files/1/0434/9699/7030/files/panda_pop_games_free.pdf
    • https://cdn.shopify.com/s/files/1/0430/6419/7273/files/ballade_pour_adeline_piano_sheet_music_free.pdf
    • https://cdn.shopify.com/s/files/1/0437/9390/7869/files/kopula.pdf
    • https://cdn.shopify.com/s/files/1/0433/4452/7528/files/jolagividen.pdf
    • https://cdn.shopify.com/s/files/1/0440/6162/2437/files/revimobexejijuwus.pdf
    • https://cdn.shopify.com/s/files/1/0444/2878/7878/files/sportster_service_manual.pdf
    • https://cdn.shopify.com/s/files/1/0430/9254/1589/files/greatest_love_of_all_piano_sheet_music.pdf
    • https://cdn.shopify.com/s/files/1/0428/8810/2051/files/vector_calculus_6th_edition_solutions.pdf
    • https://cdn.shopify.com/s/files/1/0433/0009/4112/files/zuvabonapopeku.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_off00006135.bin
c3fa1d7d0bf358cc2b1be688bd37bc77f8267b5f6f82c16b8404ae7a3cec65f9
pdf-font-stream PDF embedded font (sfnt) at offset 0x6135 5568 bytes
font_01_sfnt_off000073f4.bin
331ee5cfb3ee7a171ecba626b1974c8cf5f8641e5b3de3ff8c5ee9f99b196c8a
pdf-font-stream PDF embedded font (sfnt) at offset 0x73F4 9432 bytes