Malicious PDF — malware analysis report

Static analysis result for SHA-256 81f81088be66c456…

MALICIOUS

PDF

33.4 KB Created: 2020-08-15 12:47:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1f481aeb8aaaa0c7382a3a6ed67a4c96 SHA-1: 379b7c6ed19536a3a69e82523150c7bd92d080b0 SHA-256: 81f81088be66c456a0ef4aad37187acc83b28e339fa088b7997ce9f236173273
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a mass external link farm, with one prominent link pointing to a known malicious redirector. The document body, though partially corrupted, suggests a lure related to job promotions. The ML classifier strongly indicated maliciousness, and the presence of numerous links to external PDFs, including a malicious redirector, points towards an attempt to drive traffic to malicious infrastructure.

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=letter+format+for+promotion+in+job
    • http://files.goldeninnervision.com/uploads/1/3/1/3/131398052/8017279.pdf
    • http://files.lttn.com/uploads/1/3/0/8/130873877/1674187.pdf
    • http://files.champaignband.com/uploads/1/3/0/8/130814714/1c2f33554.pdf
    • http://files.edutechresearch.com/uploads/1/3/0/7/130740375/vogeriwa.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0431/8189/9936/files/cambios_fisiologicos_y_psicologicos_durante_el_embarazo.pdf
    • https://cdn.shopify.com/s/files/1/0427/5575/2103/files/pygame_for_python_3._5.pdf
    • https://cdn.shopify.com/s/files/1/0427/7954/1671/files/10411496273.pdf
    • https://cdn.shopify.com/s/files/1/0437/3289/3857/files/loxitunovadujugekuj.pdf
    • https://cdn.shopify.com/s/files/1/0439/4647/5678/files/control_wizard_dps_build_mod_11.pdf
    • https://cdn.shopify.com/s/files/1/0431/8681/5139/files/17960484062.pdf
    • https://cdn.shopify.com/s/files/1/0431/3268/2397/files/87551739545.pdf
    • https://cdn.shopify.com/s/files/1/0430/9955/3959/files/xigexoxisagawaxame.pdf
    • https://cdn.shopify.com/s/files/1/0432/8659/3694/files/angielski_dla_pocztkujcych_testy.pdf
    • https://cdn.shopify.com/s/files/1/0434/8998/4678/files/clinical_chemistry_bishop_6th_edition.pdf
    • https://cdn.shopify.com/s/files/1/0432/2515/3698/files/navosaxubeseb.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000470a.bin
21107c88b3717da5fddac45bb79c7ed076e7c02c9fba393166b77498881af550
pdf-font-stream PDF embedded font (sfnt) at offset 0x470A 4992 bytes
font_01_sfnt_off000057ec.bin
458b9260c780812acb0e339aa6c8b00258d39d45c5a23885a0003a214572e865
pdf-font-stream PDF embedded font (sfnt) at offset 0x57EC 9608 bytes