Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bd25f5901fc3c46…

MALICIOUS

PDF

35.5 KB Created: 2020-08-21 08:42:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0fa0ab74a5c471454b00366b85269bef SHA-1: 5ec85a4eff93f29cc8360c570c0593f882bb5242 SHA-256: 4bd25f5901fc3c46c566ec8437d365e7607ee24be1591f6ce55475bf17a2f58c
152 Risk Score

Malware Insights

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

The PDF contains a deceptive link disguised as a download for "Chemdraw free pro 8.0". This link, https://ttraff.ru/pify?keyword=chemdraw+free+pro+8.+0, points to a known malicious redirector. The document also features a large number of external PDF links, many hosted on Shopify, which is characteristic of SEO link farm abuse to obscure malicious destinations. The ML classifier 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/pify?keyword=chemdraw+free+pro+8.+0
    • http://vemerugo.13thguardspoltavaskaya.com/uploads/1/3/2/7/132740609/rojevulavi_zodof_pimegepamisipud.pdf
    • http://lavufova.collegewomensclubofdayton.org/uploads/1/3/1/4/131406361/sekoguvosojiwajik.pdf
    • http://xuseku.bibisnelderwaardbrion.com/uploads/1/3/1/8/131856166/ribefiruwobita.pdf
    • https://cdn.shopify.com/s/files/1/0438/1786/1280/files/18539307651.pdf
    • https://cdn.shopify.com/s/files/1/0430/4204/6103/files/jopifopalopenoro.pdf
    • https://cdn.shopify.com/s/files/1/0428/4982/9023/files/87328128308.pdf
    • https://cdn.shopify.com/s/files/1/0428/2833/3219/files/pdf_of_mixture_and_alligation_problems_for_competitive_exams.pdf
    • https://cdn.shopify.com/s/files/1/0434/1714/1415/files/possessivi_italiano.pdf
    • https://cdn.shopify.com/s/files/1/0432/9521/1680/files/23298505396.pdf
    • https://cdn.shopify.com/s/files/1/0430/6354/1917/files/58142417862.pdf
    • https://cdn.shopify.com/s/files/1/0433/4295/4661/files/adobe_premiere_pro_cc_tutorial_free_download.pdf
    • https://cdn.shopify.com/s/files/1/0438/2598/7734/files/efesios_hernandes_dias_lopes.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_off00004c62.bin
4e42e4c78644d7ae3fae85ec06aaddf4f41030389f735efad383eda828e296c9
pdf-font-stream PDF embedded font (sfnt) at offset 0x4C62 5436 bytes
font_01_sfnt_off00005ed2.bin
f6807464f8351c32513363ce7a4cb27d3d10b5027d2a3fee8c8644191170fc39
pdf-font-stream PDF embedded font (sfnt) at offset 0x5ED2 10192 bytes