Malicious PDF — malware analysis report

Static analysis result for SHA-256 838f7a380d6730b6…

MALICIOUS

PDF

52.2 KB Created: 2020-08-15 21:33:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c983eb81e320c5efcf5ece4ccedbb5fd SHA-1: 8ee5e16764da72ecbbb99f1a2dae6b529ca96ad2 SHA-256: 838f7a380d6730b699087797b30550c83cd92e21f96769a18b6b2f0dccc6b3e2
152 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, with a critical heuristic firing indicating it links to known malicious redirector infrastructure. Another critical heuristic identifies it as a PDF SEO link farm, containing a large number of external PDF links. The ML classifier also strongly flagged this PDF as malicious. The primary malicious IOC is the redirector URL, which is likely used to funnel victims to further malicious content or phishing sites.

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/wb?keyword=pneumonia%20intersticial%20aguda%20pdf
    • http://files.windycreek1910.com/uploads/1/3/0/7/130740138/wavirerojulu_pafumatolire_nedokafad.pdf
    • https://cdn.shopify.com/s/files/1/0432/8282/5376/files/getogamezefan.pdf
    • https://cdn.shopify.com/s/files/1/0435/6793/9743/files/lifehouse_you_and_me_chords.pdf
    • https://cdn.shopify.com/s/files/1/0431/5679/9637/files/anatomy_and_physiology_of_eye_khurana_free_download.pdf
    • https://cdn.shopify.com/s/files/1/0433/7814/7491/files/xumumoxatoguna.pdf
    • https://cdn.shopify.com/s/files/1/0433/8548/7516/files/full_mobile_movies_hollywood.pdf
    • https://cdn.shopify.com/s/files/1/0431/2632/5409/files/67211702537.pdf
    • https://cdn.shopify.com/s/files/1/0429/5196/6873/files/genikeligikuse.pdf
    • https://cdn.shopify.com/s/files/1/0434/3581/9173/files/destiny_black_armory_leveling_guide.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kerikelamizefebimu.pdf
    • https://cdn.shopify.com/s/files/1/0430/7727/1706/files/6614086362.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/fokukivovasogu.pdf
    • https://cdn.shopify.com/s/files/1/0432/4845/1739/files/android_studio_flutter_ios.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/81988232477.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_off00008804.bin
de6fc3b2c90b3362324801e788e5dd98a68ebcba46a7e453b7745c6f04496e44
pdf-font-stream PDF embedded font (sfnt) at offset 0x8804 5476 bytes
font_01_sfnt_off00009a89.bin
27d7106e4d984c8234252ce328400a8d5fb06b76c5d2fb6dc72ecb103b46170c
pdf-font-stream PDF embedded font (sfnt) at offset 0x9A89 13636 bytes