Malicious PDF — malware analysis report

Static analysis result for SHA-256 88b25ddfac51b396…

MALICIOUS

PDF

44.8 KB Created: 2020-08-19 13:41:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 17e03d7849022c20fd797a4fceef223d SHA-1: 8448904f69622181a41a00e3e3dc6a9322fa18db SHA-256: 88b25ddfac51b3968c4d0908450de0c9b46b1acd8562b144a95cd89a8cb83467
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links, including one pointing to a known malicious redirector at 'ttraff.com'. The document body, though heavily obfuscated, appears to contain text related to educational worksheets, suggesting a lure. The presence of embedded URLs and the ML classifier's high confidence indicate malicious intent, likely to redirect users to 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.com/pify?keyword=geometric+shapes+worksheets+for+4th+grade
    • http://nilasotu.candlewyckhomes.com/uploads/1/3/0/8/130813765/vifiku.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/65069223210.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/68513135127.pdf
    • https://cdn.shopify.com/s/files/1/0437/0874/3834/files/repefumidesibawij.pdf
    • https://cdn.shopify.com/s/files/1/0433/0668/0484/files/983040120.pdf
    • https://cdn.shopify.com/s/files/1/0433/4478/9653/files/30807632710.pdf
    • https://cdn.shopify.com/s/files/1/0428/8764/3303/files/girudibuge.pdf
    • https://cdn.shopify.com/s/files/1/0432/5100/7638/files/52281971784.pdf
    • https://cdn.shopify.com/s/files/1/0432/7555/0873/files/chava_kadambari_in_format.pdf
    • https://cdn.shopify.com/s/files/1/0449/1057/5771/files/maths_olympiad_books_for_class_11.pdf
    • https://cdn.shopify.com/s/files/1/0430/1363/6259/files/fijajirupegajeren.pdf
    • https://cdn.shopify.com/s/files/1/0433/5150/7112/files/67878778383.pdf
    • https://cdn.shopify.com/s/files/1/0438/2598/7741/files/ccleaner_free_getintopc.pdf
    • https://cdn.shopify.com/s/files/1/0431/9982/4032/files/staxel_dedicated_server.pdf
    • https://cdn.shopify.com/s/files/1/0430/7956/5465/files/remove_duplicate_data_in_array_golang.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000070a5.bin
635e5c5e806e5c1b9686379a665caa437d40da0e5886f7c38bb7438caad1ad4c
pdf-font-stream PDF embedded font (sfnt) at offset 0x70A5 5812 bytes
font_01_sfnt_off0000846f.bin
88c830f08373fe0a61dc738184272ff5c16298fc7638184271905bf534f794c0
pdf-font-stream PDF embedded font (sfnt) at offset 0x846F 9792 bytes