Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb319c1afedcca45…

MALICIOUS

PDF

37.8 KB Created: 2020-08-29 10:41:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3392de06e82a82d8bd5d89e5a68778d9 SHA-1: 3869cca0604470fd8c135fb04a09052f993a06ca SHA-256: bb319c1afedcca450cba0a85b9a4eb4bb987a0931e59930757556292235ad24a
152 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded links, many pointing to external PDF documents hosted on static.usrfiles.com. One of the primary links, https://ttraff.ru/wix?keyword=discovering+statistics+using+r+ebook, is flagged as a known malicious redirector. This suggests the document is part of a link farm or SEO manipulation scheme, potentially leading to malicious content or phishing pages. The ML classifier also strongly indicated maliciousness.

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/wix?keyword=discovering+statistics+using+r+ebook
    • https://static.usrfiles.com/ugd/b8c837_58bfa08929de4765a34c6c8a5e712f61.pdf
    • https://static.usrfiles.com/ugd/b8c837_b77d207c14c04e569c7a4c6da3a3e7e2.pdf
    • https://static.usrfiles.com/ugd/b8c837_9f519e095f76478abb2581925e1b4bc7.pdf
    • https://static.usrfiles.com/ugd/b8c837_22cf1212154446df87a2a48f71669641.pdf
    • https://static.usrfiles.com/ugd/b8c837_7c8bc529c4e34f1496d0b4591b5addac.pdf
    • https://cdn.shopify.com/s/files/1/0447/5292/8919/files/nucleophile_and_electrophile.pdf
    • https://cdn.shopify.com/s/files/1/0430/9444/2145/files/mawinadorosi.pdf
    • https://cdn.shopify.com/s/files/1/0429/4787/0876/files/73838084760.pdf
    • https://cdn.shopify.com/s/files/1/0430/2965/9797/files/66862331551.pdf
    • https://static.usrfiles.com/ugd/b8c837_9ad48b43fafa4531af53524faa141fbf.pdf
    • https://static.usrfiles.com/ugd/b8c837_b8813a76683e41758b0793fc6c1a0021.pdf
    • https://static.usrfiles.com/ugd/b8c837_69e02ad61c93478198e81f7fd307f054.pdf
    • https://static.usrfiles.com/ugd/b8c837_794b5c0f66064eee9cdda046c14ab03f.pdf
    • https://static.usrfiles.com/ugd/b8c837_1fd0bdb4ea354122ab036d196f5a9c5b.pdf
    • https://static.usrfiles.com/ugd/b8c837_10e29f09fdae409693f8eacb75908e09.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_off00005691.bin
74a22fbedcc3e549f2f8e0dfbbf9d6573bbe3545beadefcbc127de5bcf7fbc6a
pdf-font-stream PDF embedded font (sfnt) at offset 0x5691 5200 bytes
font_01_sfnt_off00006859.bin
92cad8be9a7836396c10718f6a5b179e803fc4c13d172bb2839e636e264ba726
pdf-font-stream PDF embedded font (sfnt) at offset 0x6859 10044 bytes