Malicious PDF — malware analysis report

Static analysis result for SHA-256 2cbf98c77c81fb6f…

MALICIOUS

PDF

44.1 KB Created: 2020-08-23 15:18:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fd529865423d4f1e54ad2a89f5f91036 SHA-1: 6ec4fb21597272c4d4f465d149622ee49d80b076 SHA-256: 2cbf98c77c81fb6f17df65d7f10fb1aa7a4961af6482505fc6fb9f16cda96206
152 Risk Score

Malware Insights

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

The PDF contains a prominent link disguised as an internship motivation letter, which redirects to a malicious URL (ttraff.com). This URL is identified as a known malicious redirector. The document also features a large number of external PDF links, many pointing to Shopify, suggesting a link farm or SEO manipulation tactic to obscure the malicious redirect. The ML classifier 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/pify?keyword=motivation+letter+for+internship+application+pdf
    • http://files.tullyink.com/uploads/1/3/2/8/132815767/tebexagazifo-vuvixefitupu-ladit.pdf
    • http://files.bobbylewislmt.com/uploads/1/3/1/8/131856698/gafaf-tobixumunobo-wigavokep.pdf
    • http://mowuw.bagelanddeli.com/uploads/1/3/0/9/130969423/6332151.pdf
    • http://files.blacksburgmiddlelibrary.com/uploads/1/3/2/6/132682745/duxamisor_xivid.pdf
    • https://cdn.shopify.com/s/files/1/0429/0835/2679/files/prepositions_of_place_exercises_perfect_english_grammar.pdf
    • https://cdn.shopify.com/s/files/1/0438/6678/3904/files/60980210537.pdf
    • https://cdn.shopify.com/s/files/1/0436/7355/1001/files/2s_complement_calculator.pdf
    • https://cdn.shopify.com/s/files/1/0452/0129/3461/files/a_k_jain_physiology_free_download.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/49186839350.pdf
    • https://cdn.shopify.com/s/files/1/0427/9032/2335/files/54562639592.pdf
    • https://cdn.shopify.com/s/files/1/0437/4170/8453/files/tukokofiluvuvulifez.pdf
    • https://cdn.shopify.com/s/files/1/0431/0577/9863/files/58140694987.pdf
    • https://cdn.shopify.com/s/files/1/0438/3372/0992/files/knime_analytics_platform_architecture.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_off00006e11.bin
56a847de50597939e538c88e20c6a3901d73577b38ce523447f41c6166364dc1
pdf-font-stream PDF embedded font (sfnt) at offset 0x6E11 5308 bytes
font_01_sfnt_off00008023.bin
d5ff520b7186dd3753c835c833319252c822b1cef5ece3da35bb8d0bc0032fff
pdf-font-stream PDF embedded font (sfnt) at offset 0x8023 10324 bytes