Malicious PDF — malware analysis report

Static analysis result for SHA-256 998da6c6343e2735…

MALICIOUS

PDF

46.8 KB Created: 2020-08-31 09:16:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d9f3fe915102fab5b767e4dbca3ea492 SHA-1: 14adf28cf8efd11f7c07301eb02d945b2e3e2813 SHA-256: 998da6c6343e2735b02edcf3b379cbcefae785474ce3901c72c6d3d9544d40cc
152 Risk Score

Malware Insights

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

The PDF contains a link that redirects to a known malicious domain, identified by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though heavily obfuscated, contains text suggesting a lure for 'leaves coloring worksheet answers'. The PDF also hosts a large number of external links, many pointing to Shopify, which is indicative of a link farm or SEO manipulation tactic. The ML classifier 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/wix?keyword=leaves+coloring+worksheet+answers
    • https://cdn.shopify.com/s/files/1/0432/4684/6107/files/78064589704.pdf
    • https://cdn.shopify.com/s/files/1/0434/7461/6472/files/south_movie_2018_list.pdf
    • https://cdn.shopify.com/s/files/1/0432/0133/1360/files/pdf_reader_and_annotator_android.pdf
    • https://cdn.shopify.com/s/files/1/0443/3536/6300/files/chapter_3_lord_of_the_flies.pdf
    • https://cdn.shopify.com/s/files/1/0435/0440/2584/files/43240898287.pdf
    • https://cdn.shopify.com/s/files/1/0437/6264/7192/files/vuridavaxuza.pdf
    • https://cdn.shopify.com/s/files/1/0428/4920/6439/files/concrete_batching_plant_layout.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/bibekejufalakudogaloseja.pdf
    • https://static.usrfiles.com/ugd/97634b_3f7ea7681691408ba685a045bf3377ff.pdf
    • https://static.usrfiles.com/ugd/934fc3_60c1a333ee8e431991b2de259b8cf3f7.pdf
    • https://static.usrfiles.com/ugd/136d07_46e6fab99f5f451d87161054b8c411db.pdf
    • https://static.usrfiles.com/ugd/409ca8_18d9ca0a22754666b017855716b18425.pdf
    • https://static.usrfiles.com/ugd/b8c837_fbcd355dca4b453e893ae47c2ec72677.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_off0000791d.bin
ee0730965b77144fcb3560f5c9c11e955028ec800c54cf0bb97db200bdc1481b
pdf-font-stream PDF embedded font (sfnt) at offset 0x791D 5220 bytes
font_01_sfnt_off00008aed.bin
a6079534013ba80cbbd2add4d0e31a665c105398871f575fc13114058a12443b
pdf-font-stream PDF embedded font (sfnt) at offset 0x8AED 10472 bytes