Malicious PDF — malware analysis report

Static analysis result for SHA-256 673984468a5c441c…

MALICIOUS

PDF

35.2 KB Created: 2020-08-23 12:18:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fa0b00d6cae5ee3ab1f1a2a58a6d6d1d SHA-1: e8b475a8da6126449de414f1a3fdb042fab49373 SHA-256: 673984468a5c441cb496699ae8565ef1c360c633e95dfd07ca43dac68af0ef97
154 Risk Score

Malware Insights

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

The PDF contains a heuristic firing for PDF_MALICIOUS_REDIRECTOR_LINK, indicating it directs users to malicious infrastructure. The document body, though heavily obfuscated, contains text related to 'Codehs basic java quiz answers' and includes the malicious URL. The ML classifier also strongly flagged this PDF as malicious. The embedded URLs suggest an attempt to distribute further malicious content or redirect users to phishing sites.

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.cc/pify?keyword=codehs+basic+java+quiz+answers
    • http://files.g7evenphotography.com/uploads/1/3/1/6/131606874/4510413.pdf
    • http://ximines.learningexchanges.org/uploads/1/3/0/7/130775565/9604509.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0436/0473/8206/files/kukusilawazefoxeronajeke.pdf
    • https://cdn.shopify.com/s/files/1/0428/5900/4070/files/48503085065.pdf
    • https://cdn.shopify.com/s/files/1/0447/7802/9213/files/pharmaceutical_guidelines_for_quality_assurance.pdf
    • https://cdn.shopify.com/s/files/1/0430/0773/8019/files/crunchbang_fix_grub.pdf
    • https://cdn.shopify.com/s/files/1/0432/0280/5921/files/jingle_bell_rock_piano_sheet_music_hard.pdf
    • https://cdn.shopify.com/s/files/1/0431/3550/0439/files/ripumunujiwuleg.pdf
    • https://cdn.shopify.com/s/files/1/0429/7372/4825/files/momugemunopuwetezup.pdf
    • https://cdn.shopify.com/s/files/1/0440/8537/9237/files/sidhu_moose_wala_afsana_khan_song.pdf
    • https://cdn.shopify.com/s/files/1/0427/9477/8791/files/34665470294.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_off00004b14.bin
434067df5703a485a8f4ed49707e99dd43a4b400a73d01ebc0fa2286bba1b49d
pdf-font-stream PDF embedded font (sfnt) at offset 0x4B14 5444 bytes
font_01_sfnt_off00005daf.bin
d37efa77fd831c94f84330bb5591b9b7490c3f7f497927917f2279e1ba4e43c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x5DAF 10184 bytes