Malicious PDF — malware analysis report

Static analysis result for SHA-256 d28537d83b447dc0…

MALICIOUS

PDF

35.7 KB Created: 2020-08-19 03:50:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 37c6984dfdc84b4ba49cdda3bbe4bd8d SHA-1: e4fb1e73ca96f3e07b4743b823ce336ebf295e05 SHA-256: d28537d83b447dc03570ce0101903b19897369e5f5e5bc55e503a3679efd3f8e
152 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and heuristics indicate it contains a large number of external links, forming a link farm. One of these links points to a known malicious redirector. The document body contains obfuscated text and embedded URLs, including the malicious redirector and several Shopify-hosted PDF files, suggesting a delivery mechanism for further malicious content.

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=newry+reporter+old+photos
    • http://lojij.talachedairygoats.com/uploads/1/3/0/8/130874629/6776047.pdf
    • https://cdn.shopify.com/s/files/1/0431/3628/6877/files/dowatoraburojag.pdf
    • https://cdn.shopify.com/s/files/1/0433/7437/9157/files/capitis_deminutio.pdf
    • https://cdn.shopify.com/s/files/1/0440/5932/8662/files/1634423838.pdf
    • https://cdn.shopify.com/s/files/1/0433/3692/5342/files/40616325309.pdf
    • https://cdn.shopify.com/s/files/1/0427/9461/4940/files/82995973890.pdf
    • https://cdn.shopify.com/s/files/1/0431/7865/5903/files/study_guide_and_intervention_answers_algebra_2.pdf
    • https://cdn.shopify.com/s/files/1/0430/3467/3301/files/tanozemilapirajenusef.pdf
    • https://cdn.shopify.com/s/files/1/0431/6971/0242/files/34868527579.pdf
    • https://cdn.shopify.com/s/files/1/0437/6847/9893/files/55833681772.pdf
    • https://cdn.shopify.com/s/files/1/0431/0794/2549/files/taworiboxexapusesex.pdf
    • https://cdn.shopify.com/s/files/1/0440/8911/4789/files/mathematical_induction_worksheet.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_off00004f39.bin
9ba4c66ff2ceec938385abe7f811e9b9b12897723336b95c4638d5f403b90644
pdf-font-stream PDF embedded font (sfnt) at offset 0x4F39 5000 bytes
font_01_sfnt_off0000604e.bin
123fa21310e10a1cfa7ecfa96c4bd2b517c9527027c7220e1ab5249821d2c256
pdf-font-stream PDF embedded font (sfnt) at offset 0x604E 9960 bytes