Malicious PDF — malware analysis report

Static analysis result for SHA-256 90739bf395fd7c4a…

MALICIOUS

PDF

38.5 KB Created: 2020-08-29 20:30:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f48cf2e6e9f56d79b7f91da8baa9d28d SHA-1: ab935ef0abec639e4ae00b9d578ae325639c9572 SHA-256: 90739bf395fd7c4a23f27a0b0db990a8ff9c2dca05357da4776fe817c9138871
152 Risk Score

Malware Insights

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

The PDF contains a significant number of embedded links, many of which point to a link farm hosted on cdn.shopify.com, and one critical link to a known malicious redirector at ttraff.com. The document body, though heavily obfuscated, contains text related to academic books and the malicious URL, suggesting a lure to trick users into visiting the redirector. The ML classifier also strongly indicated 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.com/wix?keyword=developmental+biology+gilbert+12th+edition+pdf
    • https://cdn.shopify.com/s/files/1/0433/7152/8344/files/collating_reports_definition.pdf
    • https://cdn.shopify.com/s/files/1/0447/6986/9975/files/skyrim_ctd_fix.pdf
    • https://cdn.shopify.com/s/files/1/0431/3199/4280/files/algebra_nation_practice_book_answer_key_section_2.pdf
    • https://cdn.shopify.com/s/files/1/0434/8080/9622/files/48931605844.pdf
    • https://static.usrfiles.com/ugd/93c935_ea956ea622e44abea714528f04043183.pdf
    • https://static.usrfiles.com/ugd/b8c837_4a55b82ce3a84c6fac59833af00e8dda.pdf
    • https://static.usrfiles.com/ugd/b8c837_91436a01911e49eab3aeec83c749f18e.pdf
    • https://static.usrfiles.com/ugd/b8c837_da2133d936164a218f79a8d2f4a3d882.pdf
    • https://static.usrfiles.com/ugd/97634b_d1f45168a58642a6837523978047c3c2.pdf
    • https://cdn.shopify.com/s/files/1/0433/4954/1013/files/astrochemistry_book.pdf
    • https://cdn.shopify.com/s/files/1/0434/1959/9004/files/cheppave_chirugali_audio_songs_coming.pdf
    • https://cdn.shopify.com/s/files/1/0436/3704/7449/files/wujujasij.pdf
    • https://cdn.shopify.com/s/files/1/0432/7201/1932/files/niwibibinogesimor.pdf
    • https://static.usrfiles.com/ugd/e73fea_5cc1215547754d06ac50c9e4ca3df365.pdf
    • https://static.usrfiles.com/ugd/b8c837_d349c48c4b87436dbe84a3b9d143293c.pdf
    • https://static.usrfiles.com/ugd/b8c837_375c03069b3d4bc0bc11542149eb8ceb.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_off000056cf.bin
f48242629f107c1c8e4934f85a88038d4279578a925eddd8d382b7c239a181c2
pdf-font-stream PDF embedded font (sfnt) at offset 0x56CF 5764 bytes
font_01_sfnt_off00006a4d.bin
dbe09d364c1420efc71042afcd4edd20c77391fa61cd770c0b85f94753f16936
pdf-font-stream PDF embedded font (sfnt) at offset 0x6A4D 10100 bytes