Malicious PDF — malware analysis report

Static analysis result for SHA-256 51327ac879edef1b…

MALICIOUS

PDF

50.6 KB Created: 2020-08-30 22:50:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d599d62471a15b8b9d6b19615fdd716d SHA-1: 3acc539c56b3f193346ef48e6d1b59b3ee7d3045 SHA-256: 51327ac879edef1b6cc808042634e730b4eea7823ce14d98ffd10111b5595f82
152 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as a download for educational material. The ML classifier strongly indicated maliciousness, and the PDF_MALICIOUS_REDIRECTOR_LINK heuristic fired, pointing to the URL https://ttraff.cc/wix?keyword=download+buku+belajar+bahasa+cina+pdf. This URL is likely used to deliver a secondary payload or lead the user to a phishing site.

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=download+buku+belajar+bahasa+cina+pdf
    • https://cdn.shopify.com/s/files/1/0433/0258/4480/files/sosepolivopiw.pdf
    • https://cdn.shopify.com/s/files/1/0434/7474/7545/files/84999420687.pdf
    • https://cdn.shopify.com/s/files/1/0465/5372/7126/files/guitar_lessons_for_beginners_dvd_free.pdf
    • https://cdn.shopify.com/s/files/1/0434/0839/2353/files/42649798704.pdf
    • https://static.usrfiles.com/ugd/e3c460_75476863dd944e688a82febfa838ca81.pdf
    • https://static.usrfiles.com/ugd/a91264_d571bf36474f4d93aca3e07a1099d2ed.pdf
    • https://static.usrfiles.com/ugd/9ff9b8_4808d374946e471eba91498fcc81b1ad.pdf
    • https://static.usrfiles.com/ugd/06497e_fa2a023089c747e295ff7974eac6eded.pdf
    • https://static.usrfiles.com/ugd/086daf_5c20e4eda7344ce0a2a50d01681fcd86.pdf
    • https://static.usrfiles.com/ugd/b8c837_3b3ea172b5c2452ca0f08364a1105733.pdf
    • https://cdn.shopify.com/s/files/1/0431/3484/5079/files/dave_ramsey_worksheet.pdf
    • https://cdn.shopify.com/s/files/1/0433/5557/0341/files/tutoring_flyer_template.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_off000087b2.bin
f4b0fb93b51fb632e86b9c111f1617950433dfb54c8ac2587e2d63b24997af8f
pdf-font-stream PDF embedded font (sfnt) at offset 0x87B2 5612 bytes
font_01_sfnt_off00009ad4.bin
dd6792a3551240fde6e01d18aea067516105663a018a2b81ae9e7524c990510f
pdf-font-stream PDF embedded font (sfnt) at offset 0x9AD4 10352 bytes