Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c2b01710b732e34…

MALICIOUS

PDF

41.7 KB Created: 2020-08-29 10:50:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 155c17cf9023774166765a10e67fba95 SHA-1: 8a1cea5114afde9e85fffd427a66c9676cc09a72 SHA-256: 4c2b01710b732e3444d4ef365a34faaaf2c48f254eeedf49e6a4dec544ad76fe
154 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, with one identified as a malicious redirector. The heuristic 'PDF_SEO_LINK_FARM' indicates a large number of external PDF links, suggesting a potential link farm for SEO manipulation or to distribute further malicious content. The ML classifier also strongly flagged this PDF as malicious. The document body contains garbled text and what appears to be metadata from the wkhtmltopdf tool, but no clear user-facing lure.

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/wix?keyword=funciones+con+valor+absoluto
    • https://static.usrfiles.com/ugd/b8c837_f4169acc233d41eaab9309ee208495ae.pdf
    • https://static.usrfiles.com/ugd/b8c837_14e3c7e9331d406da9326c96fd478f5d.pdf
    • https://static.usrfiles.com/ugd/b8c837_821e933222a64af9b7de43d3807d34f3.pdf
    • https://static.usrfiles.com/ugd/b8c837_c780c24a1d984b8a952094585d75b96a.pdf
    • https://static.usrfiles.com/ugd/b8c837_580e3ce26b484a26b3fff53cb95776e5.pdf
    • https://cdn.shopify.com/s/files/1/0435/6423/6968/files/wisida.pdf
    • https://cdn.shopify.com/s/files/1/0437/8951/6962/files/water_borne_diseases_and_their_prevention.pdf
    • https://cdn.shopify.com/s/files/1/0435/7314/9859/files/murder_set_pieces.pdf
    • https://cdn.shopify.com/s/files/1/0434/1969/7303/files/download_dablo_2.pdf
    • https://cdn.shopify.com/s/files/1/0441/0081/2952/files/passive_voice_continuous_tense_exercises.pdf
    • https://cdn.shopify.com/s/files/1/0429/5763/5735/files/48125527738.pdf
    • https://cdn.shopify.com/s/files/1/0431/4444/6118/files/bumuj.pdf
    • https://cdn.shopify.com/s/files/1/0427/8360/4903/files/rizalozavut.pdf
    • https://cdn.shopify.com/s/files/1/0432/7243/7910/files/nagasisafale.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_off0000648d.bin
2341a9c1819d28a2d00ebe2f4a8b782e6415a3335020832ac1c9e35f8f67fb66
pdf-font-stream PDF embedded font (sfnt) at offset 0x648D 4948 bytes
font_01_sfnt_off00007570.bin
ab0754fd26a36a768d3e7774f6e347bbc2e3bcda130894150e159f4972d03091
pdf-font-stream PDF embedded font (sfnt) at offset 0x7570 10820 bytes