Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca735a260c5bc997…

MALICIOUS

PDF

41.6 KB Created: 2020-08-08 21:13:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f6c2bd8679cebe36bd8c8eb26daa8e10 SHA-1: cfb6f4f4cd43bcff662ff733bb0f4c86772b8221 SHA-256: ca735a260c5bc997ac32bed48b417905ff43ed10026b9d590e7817571f7cb7a7
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with one specifically pointing to a known malicious redirector infrastructure. The heuristic 'PDF_SEO_LINK_FARM' indicates a mass external PDF link farm, suggesting the document is designed to host numerous links. The ML classifier strongly supports the malicious verdict. No scripts were extracted, and the document body is heavily obfuscated, but the presence of numerous links is the primary indicator 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.ru/pify?keyword=advanced+market+leader+business+english+course+book+3rd+edition+pdf
    • http://files.giannidicaro.com/uploads/1/3/2/7/132712415/5a345b6.pdf
    • http://files.hmfsoti.net/uploads/1/3/2/8/132814552/2b0d276.pdf
    • http://files.journeyofaleukemiawarrior.com/uploads/1/3/2/3/132303009/39717fc.pdf
    • https://cdn.shopify.com/s/files/1/0431/3966/1986/files/9343619061.pdf
    • https://cdn.shopify.com/s/files/1/0438/3332/7776/files/tukimiberumogudibu.pdf
    • https://cdn.shopify.com/s/files/1/0430/9676/8665/files/55403646297.pdf
    • https://cdn.shopify.com/s/files/1/0431/5483/3564/files/31008812786.pdf
    • https://cdn.shopify.com/s/files/1/0434/2143/4005/files/diwinuliro.pdf
    • https://cdn.shopify.com/s/files/1/0428/8456/3110/files/63471843809.pdf
    • https://cdn.shopify.com/s/files/1/0429/9902/1717/files/sazigafutojikafivomuzofup.pdf
    • https://cdn.shopify.com/s/files/1/0430/2897/1681/files/mupulop.pdf
    • https://cdn.shopify.com/s/files/1/0434/9096/7714/files/numerologia_tantrica_kundalini.pdf
    • https://cdn.shopify.com/s/files/1/0438/6773/4171/files/crema_de_vainilla_artemisa_tellez.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_off0000606c.bin
4816e0199a51764375ba9ff10bc7da0047d5716184e4946fbfb3d496d5853e72
pdf-font-stream PDF embedded font (sfnt) at offset 0x606C 5984 bytes
font_01_sfnt_off000074ac.bin
bbcc2562c4f13990ece01b3a062eb2a1d6acf6366696df5b28eee292a9498231
pdf-font-stream PDF embedded font (sfnt) at offset 0x74AC 10464 bytes