Malicious PDF — malware analysis report

Static analysis result for SHA-256 921b7b041cb23c93…

MALICIOUS

PDF

42.5 KB Created: 2020-08-29 02:59:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0db324b8fd36a1b963c13727dda9057f SHA-1: 4bef5be9bfa19395d728c60e4154d64b6ccab1b6 SHA-256: 921b7b041cb23c934ffa4ecf1d0fe8c60c669438ba6c40e06bafac9836e1faab
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF file contains a significant number of embedded links, with one identified as a malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though partially corrupted, contains the URL 'https://ttraff.com/wix?keyword=ruidos+de+korotkoff+que+son', which is flagged as a malicious redirector. The presence of a link farm suggests an attempt to distribute malicious content or phish users.

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/wix?keyword=ruidos+de+korotkoff+que+son
    • https://static.usrfiles.com/ugd/b8c837_015a73c995244b06aa1f950515001515.pdf
    • https://static.usrfiles.com/ugd/b8c837_4d6113f6fb5540a5ba59512849ae614a.pdf
    • https://static.usrfiles.com/ugd/b8c837_26c2707469a849988936b790c91231cd.pdf
    • https://static.usrfiles.com/ugd/b8c837_239e84ec9ba74095b28d89f3733aafcd.pdf
    • https://static.usrfiles.com/ugd/b8c837_305de594db164e7fbf09200932dfe48d.pdf
    • https://static.usrfiles.com/ugd/b8c837_69260b6ea10e4c69897655aa39b009b2.pdf
    • https://static.usrfiles.com/ugd/b8c837_dfc587d6c35a4f17877ed0369fc95c21.pdf
    • https://cdn.shopify.com/s/files/1/0437/1077/5464/files/v3rm_print_position_and_copy_text.pdf
    • https://cdn.shopify.com/s/files/1/0433/6232/0536/files/napimipib.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/33435760041.pdf
    • https://cdn.shopify.com/s/files/1/0432/2784/0675/files/digepenikoxawek.pdf
    • https://cdn.shopify.com/s/files/1/0436/1093/1358/files/15680685432.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005bae.bin
6dc1d0950fc1ac917dc5f09bf8bff004ef9b7a5c5ad9c25325c1ada981742c55
pdf-font-stream PDF embedded font (sfnt) at offset 0x5BAE 4736 bytes
font_01_sfnt_off00006bd5.bin
6f931fbc9fa5ed8250d3a680628c0f57f509ae183ee160f41ee883302bb89f66
pdf-font-stream PDF embedded font (sfnt) at offset 0x6BD5 10468 bytes
font_02_sfnt_off00008f98.bin
7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71
pdf-font-stream PDF embedded font (sfnt) at offset 0x8F98 4324 bytes