Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b8cbda3c94f2fbe…

MALICIOUS

PDF

34.0 KB Created: 2020-08-13 15:31:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 344729ec6cca9b479e1f3e2efd0de74b SHA-1: 7cce6f4e7182ec2c89afacb8e52e8ef06193d85d SHA-256: 4b8cbda3c94f2fbe7969da4d1fb89ae12af8b23df445291f0252b5bb334004e8
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one specifically pointing to a known malicious redirector. The document body, though partially corrupted, includes the text 'Libro antigona pdf gratis' and the malicious URL, suggesting a lure for users seeking free content. The presence of a large number of external links, many hosted on Shopify, indicates a potential link farm or SEO manipulation tactic. The ML classifier also strongly flagged this PDF as malicious.

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.ru/pify?keyword=libro+antigona+pdf+gratis
    • http://files.fourseasonslodge.com/uploads/1/3/0/9/130969322/nisotefo_berofel_nezururosimuvu_lukaj.pdf
    • http://files.laconversationbakery.com/uploads/1/3/1/0/131070378/kijarubedizi.pdf
    • http://files.jamillson.com/uploads/1/3/0/9/130969053/9631397.pdf
    • https://cdn.shopify.com/s/files/1/0434/0154/3831/files/vmware_workstation_15_pro_license.pdf
    • https://cdn.shopify.com/s/files/1/0435/8701/0715/files/bebitogu.pdf
    • https://cdn.shopify.com/s/files/1/0432/0840/9250/files/wordpress_change_font.pdf
    • https://cdn.shopify.com/s/files/1/0437/2122/8440/files/aircraft_engine_design_jack_d._mattingly.pdf
    • https://cdn.shopify.com/s/files/1/0450/9528/8984/files/roger_bastide_o_candombl_da_bahia.pdf
    • https://cdn.shopify.com/s/files/1/0432/6604/8165/files/57863927376.pdf
    • https://cdn.shopify.com/s/files/1/0429/1110/5183/files/75517793685.pdf
    • https://cdn.shopify.com/s/files/1/0429/7300/3939/files/megakurid.pdf
    • https://cdn.shopify.com/s/files/1/0438/6367/0939/files/exercicios_de_analise_combinatoria_e_probabilidade.pdf
    • https://cdn.shopify.com/s/files/1/0432/3000/3357/files/muwojem.pdf
    • https://cdn.shopify.com/s/files/1/0428/8741/3923/files/56426550118.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_off000048a9.bin
ee393909ea7f10d89d5c20d783979ba107347599ce50ca6da37373b2789af045
pdf-font-stream PDF embedded font (sfnt) at offset 0x48A9 5260 bytes
font_01_sfnt_off00005a8e.bin
edbfdb149277f4d6a6ff4be8433dcd296d8ac4c02c00c3448e80f056749364d7
pdf-font-stream PDF embedded font (sfnt) at offset 0x5A8E 10232 bytes