Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfa4da6d942ba423…

MALICIOUS

PDF

41.0 KB Created: 2020-08-13 21:48:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0db83b47dc2f0746675f3770a2c13e62 SHA-1: 7501437b5f48d6fb0af3cbaa1e69691f7496437e SHA-256: dfa4da6d942ba42311f373a43bb2c76943897d2bb6044904ddad74e71a9b4a60
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a link farm designed to redirect users to malicious infrastructure, specifically identified by the 'PDF_MALICIOUS_REDIRECTOR_LINK' heuristic. The document body, though partially corrupted, contains text related to 'school border paper template free' and includes the malicious redirector URL. The ML classifier strongly indicated maliciousness. The primary attack vector appears to be luring users to a malicious site via a deceptive document.

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=school+border+paper+template+free
    • http://rexoliso.mezzanineboutique.com/uploads/1/3/0/8/130813612/fomidutinosado.pdf
    • http://files.prime8coding.co.uk/uploads/1/3/1/4/131406505/penavi.pdf
    • http://wakakod.btcjp.co/uploads/1/3/1/6/131606289/zujel.pdf
    • https://cdn.shopify.com/s/files/1/0435/2904/4119/files/dojukuxe.pdf
    • https://cdn.shopify.com/s/files/1/0429/9902/1717/files/26896065155.pdf
    • https://cdn.shopify.com/s/files/1/0433/7840/9622/files/62331640677.pdf
    • https://cdn.shopify.com/s/files/1/0437/1631/3242/files/847273226.pdf
    • https://cdn.shopify.com/s/files/1/0429/6779/3820/files/13068506459.pdf
    • https://cdn.shopify.com/s/files/1/0430/4211/1637/files/la_clippers_schedule_2020_20.pdf
    • https://cdn.shopify.com/s/files/1/0429/5042/6780/files/kavebepimezobolenaxazixa.pdf
    • https://cdn.shopify.com/s/files/1/0434/1969/7310/files/julumawame.pdf
    • https://cdn.shopify.com/s/files/1/0434/5901/8919/files/angular_js_dropdown_menu.pdf
    • https://cdn.shopify.com/s/files/1/0432/9222/9797/files/xoxeginovapatemobido.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_off0000614d.bin
5517815ad9b60cac4574d9d8b17456bb97ed097649445c1070bc26a23e01feaf
pdf-font-stream PDF embedded font (sfnt) at offset 0x614D 5460 bytes
font_01_sfnt_off000073ae.bin
534c7a9125c540c8f840b381f6282834baf6a39b4c758b0cd496d7ef38ef95d4
pdf-font-stream PDF embedded font (sfnt) at offset 0x73AE 10428 bytes