Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4d4241294e6b713…

MALICIOUS

PDF

39.6 KB Created: 2020-08-05 02:37:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f41ebc792791650559b3d5ff7dc9de23 SHA-1: eb39df5e5be97c02a99a4516e7bb58c1231e1704 SHA-256: a4d4241294e6b713828d0d4ba3cbb8db1d1b0d34e6a9b4c79d1f2ff65dece391
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a significant number of embedded links, with one pointing to a known malicious redirector. The heuristic 'PDF_SEO_LINK_FARM' indicates a mass external PDF link farm, suggesting a deceptive or manipulative purpose. The ML classifier also strongly flagged this PDF as malicious. The document body itself is heavily obfuscated and contains the primary malicious URL.

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/wb?keyword=charts%20and%20graphs%20worksheets
    • http://files.blde.org/uploads/1/3/0/8/130873791/wetomipepawado-zotesusitonu.pdf
    • http://files.californiadaylilies.com/uploads/1/3/0/7/130739443/kadape.pdf
    • http://files.deeperwaterscounseling.org/uploads/1/3/0/7/130775607/kodozowenobudu-kajutuzakike-bosoguvuwegoxev.pdf
    • http://files.thenyancave.com/uploads/1/3/0/7/130739833/5421577.pdf
    • http://files.movieseaon.com/uploads/1/3/0/8/130814831/komorinasit.pdf
    • https://cdn.shopify.com/s/files/1/0438/9981/4056/files/a_pictorial_cyclopedia_of_philippine_ornamental_plants.pdf
    • https://cdn.shopify.com/s/files/1/0435/0833/4744/files/64324859046.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/fakuwonilojovaxibudebu.pdf
    • https://cdn.shopify.com/s/files/1/0433/2499/7800/files/jugerukafiboben.pdf
    • https://cdn.shopify.com/s/files/1/0431/6073/1808/files/40th_bcs_mcq_result_2020.pdf
    • https://cdn.shopify.com/s/files/1/0430/2631/7473/files/rijud.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/94448736580.pdf
    • https://cdn.shopify.com/s/files/1/0437/7097/0274/files/53860429113.pdf
    • https://cdn.shopify.com/s/files/1/0432/1820/6887/files/perky_calling_instrumental_download_free.pdf
    • https://cdn.shopify.com/s/files/1/0427/4677/3660/files/88444255356.pdf
    • https://cdn.shopify.com/s/files/1/0432/2256/5032/files/antenatal_care_guidelines.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_off00005e6d.bin
dca51fe205feee14c8244c23a4ba41c58bb39dc6887c19286e7b06953fc5caf2
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E6D 5252 bytes
font_01_sfnt_off00007050.bin
8f857f1856cf250efd9fbf7f6f2d5407cd419778f6ff5f124e114a04c106c237
pdf-font-stream PDF embedded font (sfnt) at offset 0x7050 9832 bytes