Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b16aaade96ca867…

MALICIOUS

PDF

46.4 KB Created: 2020-08-01 19:54:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 07a657c6c8917177009d6b039256398f SHA-1: c670f8b19744a8d5920f99b7fcf046bf6aa1879e SHA-256: 9b16aaade96ca86721e2c72c95df4480ad0ea1918dd756a0773bdfc9a9851a7d
152 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as an MBA recommendation letter, which leads to a link farm of numerous other PDFs. This indicates a social engineering attempt to direct users to potentially harmful content. The ML classifier strongly supports the malicious nature of this PDF.

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.com/pify?keyword=sample+mba+recommendation+letter
    • http://files.heartofthewest.org/uploads/1/3/1/6/131606094/wemug.pdf
    • http://files.alittlepeaceayurveda.com/uploads/1/3/1/6/131606284/bawerexi.pdf
    • http://files.thewaveindustries.com/uploads/1/3/1/4/131413837/a1b902b2.pdf
    • http://files.kocanada-usa.com/uploads/1/3/1/4/131437538/zorodoke.pdf
    • https://cdn.shopify.com/s/files/1/0429/8804/4442/files/74862163817.pdf
    • https://cdn.shopify.com/s/files/1/0438/9961/7448/files/70099774863.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/dubisetebezurazoxodo.pdf
    • https://cdn.shopify.com/s/files/1/0431/8894/5064/files/gifeguguvizetarov.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/6735074847.pdf
    • https://cdn.shopify.com/s/files/1/0440/2269/4038/files/tuborimeduzajila.pdf
    • https://cdn.shopify.com/s/files/1/0430/0541/1481/files/37496657522.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/wexanenivoxepabulolud.pdf
    • https://cdn.shopify.com/s/files/1/0432/5507/0880/files/69290391446.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/sovir.pdf
    • https://cdn.shopify.com/s/files/1/0430/8277/6725/files/jikazudujezulumigeser.pdf
    • https://cdn.shopify.com/s/files/1/0435/8370/1151/files/smell_yo_dick.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_off0000772f.bin
d2b3c91d64fe890c129ec223a6c6ee6ee3c54e027ab736943ec3d0fd692690eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x772F 5284 bytes
font_01_sfnt_off00008902.bin
84f09657102a9327975f7991175d26b800edc3b4f38de2aad103622c792a460e
pdf-font-stream PDF embedded font (sfnt) at offset 0x8902 10540 bytes