Malicious PDF — malware analysis report

Static analysis result for SHA-256 83914541dc76131e…

MALICIOUS

PDF

52.6 KB Created: 2020-08-31 17:30:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 33b12abd204133a849b0e72673aa093b SHA-1: 35275aeddf124ffa6b172714574438aabc64c5a9 SHA-256: 83914541dc76131ebedcf65aeec2ffc5cfccfb5e02bf260fe8b29ad1116941d8
152 Risk Score

Malware Insights

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

The PDF contains a prominent link to 'https://ttraff.cc/wix?keyword=biorefinery+book+pdf', which is flagged as a malicious redirector. The document body, though partially corrupted, also contains this URL and appears to be a lure for a 'Biorefinery book pdf'. The presence of a large number of external PDF links, many pointing to Shopify, suggests a link farm or SEO manipulation tactic to distribute malicious content. The ML classifier strongly indicates maliciousness.

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=biorefinery+book+pdf
    • https://cdn.shopify.com/s/files/1/0449/9714/8836/files/17_key_kalimba_sheet_music.pdf
    • https://cdn.shopify.com/s/files/1/0433/4331/5102/files/79368927476.pdf
    • https://cdn.shopify.com/s/files/1/0433/7552/6042/files/free_printable_worksheets_for_1st_grade.pdf
    • https://cdn.shopify.com/s/files/1/0430/1537/2953/files/50447267116.pdf
    • https://cdn.shopify.com/s/files/1/0437/7791/7085/files/mitsubishi_tractor_manual.pdf
    • https://static.usrfiles.com/ugd/217d68_aed7c2697c924d3480dbbb2990f6aae7.pdf
    • https://static.usrfiles.com/ugd/b8c837_d6e82f2d796d4f2f9dab1a9d9eb3a729.pdf
    • https://static.usrfiles.com/ugd/4bb894_c010c527da8841299dca3236861b6df8.pdf
    • https://static.usrfiles.com/ugd/4b7290_7ab48748fde34182936ba85f87b7047f.pdf
    • https://static.usrfiles.com/ugd/95089d_473c6dddf52e4939b08ebecab85867f5.pdf
    • https://static.usrfiles.com/ugd/b8c837_76d2d8ee02c84bb3b86aaea4000516f3.pdf
    • https://static.usrfiles.com/ugd/4dd980_5de7ce065f2344a18b67279432781514.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_off000091cb.bin
42f1a927ec4e8953922612d15e9569396a54c1f597db3ba247d791a03b7081a0
pdf-font-stream PDF embedded font (sfnt) at offset 0x91CB 4968 bytes
font_01_sfnt_off0000a2d0.bin
971efdb9ca1f8dd66357ee8362d8697f26bda24e464aac70dbd39b08b42a7cd5
pdf-font-stream PDF embedded font (sfnt) at offset 0xA2D0 10324 bytes