Malicious PDF — malware analysis report

Static analysis result for SHA-256 65f2ba160356fc7a…

MALICIOUS

PDF

40.9 KB Created: 2020-08-19 11:53:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 6b631f27f748e47babfaa8c0877ca0c2 SHA-1: 37c6d1a3780714a2544d029194d65b3d88c269e4 SHA-256: 65f2ba160356fc7aebd578712cadb2bdf91a5fc536551006adfaa6a2df5c20a0
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to potentially malicious redirectors like 'ttraff.ru'. The document body, though heavily obfuscated, contains references to 'algebra worksheets online' and includes the malicious URL, suggesting a lure to disguise malicious activity. The ML classifier strongly indicated maliciousness, and the presence of numerous external links points to a link farm or SEO poisoning tactic.

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.ru/pify?keyword=algebra+worksheets+online
    • http://files.orbisholding.com/uploads/1/3/1/3/131381799/runini.pdf
    • http://files.carolnorrismft.com/uploads/1/3/0/8/130814343/6274192.pdf
    • http://files.14thandmainchurchofchrist.com/uploads/1/3/1/1/131164310/gatovikido-pegetimudenazit-ximefefuwipe.pdf
    • http://files.thegreedycouple.com/uploads/1/3/0/9/130969192/e916aee.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0433/8122/7672/files/4052720225.pdf
    • https://cdn.shopify.com/s/files/1/0437/2335/8358/files/tirapuwowesubenewuto.pdf
    • https://cdn.shopify.com/s/files/1/0435/4709/9290/files/bevewu.pdf
    • https://cdn.shopify.com/s/files/1/0434/2946/2165/files/nervous_system_worksheet_high_school_answers.pdf
    • https://cdn.shopify.com/s/files/1/0428/8679/1334/files/9955640005.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/29025511016.pdf
    • https://cdn.shopify.com/s/files/1/0434/0878/5562/files/minecraft_auto_miner_script.pdf
    • https://cdn.shopify.com/s/files/1/0432/7328/9888/files/perufiwevukujobepuranesav.pdf
    • https://cdn.shopify.com/s/files/1/0431/3363/2661/files/7455487448.pdf
    • https://cdn.shopify.com/s/files/1/0430/5318/7223/files/mudurufalijugebifoxef.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_off0000625a.bin
04c2a418a9d5248b97bc8e2e287215db1c412c1ae75b528c34a02be00d8d69cb
pdf-font-stream PDF embedded font (sfnt) at offset 0x625A 5232 bytes
font_01_sfnt_off0000742d.bin
65aeb7c52f467e2956c665893b6196240f048e7f25c399b1ba6b34210adb5156
pdf-font-stream PDF embedded font (sfnt) at offset 0x742D 10248 bytes