Malicious PDF — malware analysis report

Static analysis result for SHA-256 83037134ca22b32d…

MALICIOUS

PDF

40.1 KB Created: 2020-08-31 03:21:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2c9c017cfdd316a9fa54484d89a9ec6b SHA-1: eb0d0f1f9c1e9652787d0398365ba9b8b91e28de SHA-256: 83037134ca22b32d21ba3eb5de742df4504cc1f078b0a344927f9426eb49528c
162 Risk Score

Malware Insights

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

The PDF contains embedded links that redirect to malicious infrastructure, as indicated by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though heavily obfuscated, contains text suggesting it is a 'solucionario' (solution manual) and includes the malicious URL. The ML classifier also strongly flagged this PDF as malicious. The presence of numerous external PDF links, many pointing to benign Shopify URLs, suggests a link farm or SEO manipulation tactic to disguise the malicious redirector.

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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=solucionario+mataix+mecanica+de+flui
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0434/5102/3526/files/10066023560.pdf
    • https://cdn.shopify.com/s/files/1/0462/6766/2490/files/decimal_division_worksheet_grade_5.pdf
    • https://cdn.shopify.com/s/files/1/0433/0127/3750/files/cannibal_holocaust_movie_in_tamil_dubbed.pdf
    • https://cdn.shopify.com/s/files/1/0427/9477/8791/files/pidepegu.pdf
    • https://cdn.shopify.com/s/files/1/0430/8022/0826/files/drinkwell_platinum_manual.pdf
    • https://cdn.shopify.com/s/files/1/0447/8572/9685/files/galazodulute.pdf
    • https://cdn.shopify.com/s/files/1/0434/5954/3192/files/tepasivivuwuwetes.pdf
    • https://static.usrfiles.com/ugd/b8c837_32bc560b756d44e78d1964fecf29cc72.pdf
    • https://static.usrfiles.com/ugd/b8c837_ce64934b18b9454eb1cd4b0ec1c38508.pdf
    • https://static.usrfiles.com/ugd/c3f88d_cd9e4b2277a44fd4b18461ebcac7f776.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000604e.bin
9115f86c26fba81fc269dbd194155c890107eb14e9f4630dccf8b68d80af1915
pdf-font-stream PDF embedded font (sfnt) at offset 0x604E 5160 bytes
font_01_sfnt_off000071c0.bin
228cfb68b92455740f6c887ecc2ddec1e7d83500ac146ab56fb243cf7f26abda
pdf-font-stream PDF embedded font (sfnt) at offset 0x71C0 10052 bytes