Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1bf8bc5b40acb8e…

MALICIOUS

PDF

41.3 KB Created: 2020-08-28 02:11:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f90a104267be3a80db3927636910a81f SHA-1: 810f7c8da6463d1641a69f7727756f363efd6969 SHA-256: a1bf8bc5b40acb8e3f7e72f4a16ef306b85dfb115086720570619939b1b4b5e2
152 Risk Score

Malware Insights

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

The PDF document contains numerous links, presented as free book downloads, to a known malicious redirector at 'ttraff.cc'. The ML classifier strongly indicated maliciousness, and the presence of a redirector URL confirms the intent to lead users to potentially harmful content. No scripts were extracted, and the document body was heavily obfuscated, but the link farm and redirector are sufficient indicators of malicious intent.

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/pify?keyword=cardiac+nursing+books+free+download
    • http://kabak.chrisball-student.com/uploads/1/3/1/0/131070894/1672640.pdf
    • https://cdn.shopify.com/s/files/1/0435/9811/9071/files/ifrs_16_leases_illustrative_examples.pdf
    • https://cdn.shopify.com/s/files/1/0438/0911/2226/files/70430058503.pdf
    • https://cdn.shopify.com/s/files/1/0437/6789/0069/files/data_mining_tutorial_point_download.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/zemeletitofugawekabol.pdf
    • https://cdn.shopify.com/s/files/1/0429/1811/7543/files/fetefurobebafolalulamoj.pdf
    • https://cdn.shopify.com/s/files/1/0448/0414/5309/files/promissory_note_for_personal_loan.pdf
    • https://cdn.shopify.com/s/files/1/0428/8679/1334/files/wonijeruxaz.pdf
    • https://cdn.shopify.com/s/files/1/0430/6472/1562/files/medium_density_fibreboard_sheets.pdf
    • https://cdn.shopify.com/s/files/1/0458/6458/3321/files/lucifer_season_2_episode_2.pdf
    • https://cdn.shopify.com/s/files/1/0429/3070/0455/files/11992981979.pdf
    • https://cdn.shopify.com/s/files/1/0432/8115/4198/files/nbi_online_registration_form.pdf
    • https://cdn.shopify.com/s/files/1/0433/2870/0571/files/chernobyl_disaster.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_off000063a3.bin
d93086c621b2afb4b2e6332a90a92a38e7f75dccdb8eeafd7aee4edf8048fd07
pdf-font-stream PDF embedded font (sfnt) at offset 0x63A3 5392 bytes
font_01_sfnt_off0000761a.bin
13c86e617ca7eddb7103c23121a0b9381b69302d2785aca01aa6dcb0d5dc5885
pdf-font-stream PDF embedded font (sfnt) at offset 0x761A 10108 bytes