Malicious PDF — malware analysis report

Static analysis result for SHA-256 be31d9872a50adc4…

MALICIOUS

PDF

43.1 KB Created: 2020-09-02 00:05:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d538940d9bd2e9e95e50abe2d1024c15 SHA-1: 33b187d5ffca03aa1b0222307bacc6a602817b01 SHA-256: be31d9872a50adc49b3ab9b053c5db2cc57d174d1c255249a88d379b9b0677b9
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF document contains a large number of external links, many of which point to benign content on Shopify. However, one critical link redirects to `https://ttraff.cc/wix?keyword=letter+c+worksheets+for+preschool+pdf`, which is identified as a malicious redirector. The ML classifier also strongly flagged this PDF as malicious. The document body, though partially corrupted, contains text related to 'letter c worksheets for preschool pdf', suggesting a lure to disguise the malicious redirection.

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/wix?keyword=letter+c+worksheets+for+preschool+pdf
    • https://cdn.shopify.com/s/files/1/0437/1709/9675/files/rorubunavadubomiroput.pdf
    • https://cdn.shopify.com/s/files/1/0431/4929/5776/files/jimexoweti.pdf
    • https://cdn.shopify.com/s/files/1/0434/5580/7640/files/deneserulikivebojogomone.pdf
    • https://static.usrfiles.com/ugd/b8c837_5ecd898ac8d74c389ba3a94c5d426505.pdf
    • https://cdn.shopify.com/s/files/1/0428/7738/6918/files/89510170708.pdf
    • https://cdn.shopify.com/s/files/1/0429/4112/0679/files/american_gods_episode_3_torrent.pdf
    • https://cdn.shopify.com/s/files/1/0436/7355/1001/files/2s_complement_calculator.pdf
    • https://cdn.shopify.com/s/files/1/0432/7620/6240/files/33365606103.pdf
    • https://cdn.shopify.com/s/files/1/0436/8039/9510/files/rinupojalusixiziserawumow.pdf
    • https://static.usrfiles.com/ugd/b8c837_7f476750cf7845febaeef278ee60f847.pdf
    • https://static.usrfiles.com/ugd/a2e20a_e0a369940a9d44198c6681873e65fbda.pdf
    • https://static.usrfiles.com/ugd/1479de_f1de20e0b8144e10be54286fbff19a33.pdf
    • https://static.usrfiles.com/ugd/d78803_855ce6aca2c040a4a9cb467de1a1202d.pdf
    • https://static.usrfiles.com/ugd/f515ca_6be5f1eb3eaa4e2cb1cd5e97ea66c2b3.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_off00006920.bin
9e9eae534f47bf4b6627f0d5eebf6bf1a1c8535f4665d74860e352027993ea7c
pdf-font-stream PDF embedded font (sfnt) at offset 0x6920 5132 bytes
font_01_sfnt_off00007aad.bin
4d7e32ea0fd98139ba98e28e8893b0b2bab63521fe1151ef62fbc1ae645b9617
pdf-font-stream PDF embedded font (sfnt) at offset 0x7AAD 10780 bytes