Malicious PDF — malware analysis report

Static analysis result for SHA-256 b44d0c2ce67fff85…

MALICIOUS

PDF

43.0 KB Created: 2020-08-22 12:07:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 20fb916391a3d580750a6d05425f179a SHA-1: 8a8d813a4882d9c6e0072f6a76db309e4bbb07eb SHA-256: b44d0c2ce67fff85881577d21b03f90a4c805a48b8513430758251483cc520bc
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains a malicious redirector link disguised as a tax-related query, aiming to lure users to a harmful site. The ML classifier strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains the malicious URL and several other URLs hosted on Shopify, likely part of a link farm to improve search engine ranking for 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.cc/pify?keyword=what+does+allowance+mean+in+tax+forms
    • http://files.terwilligercpa.com/uploads/1/3/0/7/130776230/wilemevokisa.pdf
    • http://xivejiwor.theconferenceofbirds.com/uploads/1/3/2/8/132814439/sixugalifapawiteki.pdf
    • https://cdn.shopify.com/s/files/1/0440/6162/2437/files/88682993981.pdf
    • https://cdn.shopify.com/s/files/1/0429/8699/5863/files/160154444.pdf
    • https://cdn.shopify.com/s/files/1/0437/4285/5319/files/rebepim.pdf
    • https://cdn.shopify.com/s/files/1/0443/0639/9388/files/14816760733.pdf
    • https://cdn.shopify.com/s/files/1/0433/6805/4949/files/tejenog.pdf
    • https://cdn.shopify.com/s/files/1/0430/5272/8474/files/ansible_playbook_tutorial.pdf
    • https://cdn.shopify.com/s/files/1/0437/5022/8119/files/duziwapam.pdf
    • https://cdn.shopify.com/s/files/1/0428/2076/3804/files/kajijupajaramexorufesip.pdf
    • https://cdn.shopify.com/s/files/1/0439/2986/2312/files/momezumorefujosejemot.pdf
    • https://cdn.shopify.com/s/files/1/0432/3636/0351/files/45161863109.pdf
    • https://cdn.shopify.com/s/files/1/0429/8529/1937/files/encyclopedia_dictionary_download.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_off000069ba.bin
cbb164879b9aca834117c6eb66fc10f43375109e3e9ef374ab8fd5ac05cd90d3
pdf-font-stream PDF embedded font (sfnt) at offset 0x69BA 5432 bytes
font_01_sfnt_off00007c1d.bin
d4ba954118a2f5c843478bb884d72fe28815c4bfc3fb149688565cdff88627e8
pdf-font-stream PDF embedded font (sfnt) at offset 0x7C1D 10196 bytes