Malicious PDF — malware analysis report

Static analysis result for SHA-256 37c7d49a66c2a9a0…

MALICIOUS

PDF

43.2 KB Created: 2020-08-16 20:40:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c5bd694c96710c94ff3f4ee44ba8d64b SHA-1: 891f2a57e49b31927c565633b3c21c4c110bb717 SHA-256: 37c7d49a66c2a9a0f0d0fe49e9c723a2bfc2dfb07993438e93a78a550ab104da
152 Risk Score

Malware Insights

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

The PDF contains a link that redirects to a malicious URL, disguised as a 'grammar check app free' download. This is further supported by heuristics indicating a malicious redirector link and a PDF link farm. The ML classifier strongly flagged this PDF as malicious. The primary intent appears to be social engineering users into visiting a malicious site.

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=grammar+check+app+free
    • http://files.texantoweroa.org/uploads/1/3/0/7/130775368/d2b4c12.pdf
    • https://cdn.shopify.com/s/files/1/0434/4443/7142/files/sevij.pdf
    • https://cdn.shopify.com/s/files/1/0432/5877/3662/files/resinulol.pdf
    • https://cdn.shopify.com/s/files/1/0433/9469/5318/files/dawuxodudo.pdf
    • https://cdn.shopify.com/s/files/1/0429/6838/3642/files/temaviputuzigadif.pdf
    • https://cdn.shopify.com/s/files/1/0437/7955/5486/files/xipepelixirepavisewepako.pdf
    • https://cdn.shopify.com/s/files/1/0433/3712/1951/files/49378259083.pdf
    • https://cdn.shopify.com/s/files/1/0430/0741/0329/files/93078447232.pdf
    • https://cdn.shopify.com/s/files/1/0438/3372/0992/files/tisagak.pdf
    • https://cdn.shopify.com/s/files/1/0437/5258/7415/files/57419539422.pdf
    • https://cdn.shopify.com/s/files/1/0433/4062/8133/files/sigeb.pdf
    • https://cdn.shopify.com/s/files/1/0431/6200/9760/files/worksheets_on_imperative_sentences.pdf
    • https://cdn.shopify.com/s/files/1/0436/9963/4330/files/certificate_of_conformity_mercedes_uk.pdf
    • https://cdn.shopify.com/s/files/1/0434/0691/7799/files/xalijazo.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_off0000604e.bin
9a301cbc43bfca08c2d53c5fca1d535eac7a4f45315a8e75f66f3479cd51a171
pdf-font-stream PDF embedded font (sfnt) at offset 0x604E 4584 bytes
font_01_sfnt_off00006fd6.bin
b8f70aed55b43cd5fa940d8942cf152ce9571e4bf99d16ecd6d322666571bf68
pdf-font-stream PDF embedded font (sfnt) at offset 0x6FD6 10036 bytes
font_02_sfnt_off0000923f.bin
1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e
pdf-font-stream PDF embedded font (sfnt) at offset 0x923F 4324 bytes