Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d78b7bf5b50b193…

MALICIOUS

PDF

50.4 KB Created: 2020-08-08 15:55:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1d165ed7e61b5b5183a39d1c7389a740 SHA-1: a293cf54a7bac63851325a1b6dff239e24aa2b0b SHA-256: 3d78b7bf5b50b193105229f03802bfc85d34d11280cd21429e545fd5e3f643ce
152 Risk Score

Malware Insights

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

The PDF document exhibits characteristics of a link farm or SEO poisoning attack. It contains a large number of embedded links, with the primary redirector URL pointing to a known malicious infrastructure. The ML classifier strongly flagged this PDF as malicious, and the heuristic rules confirm the presence of a malicious redirector and a link farm. The document body itself is largely obfuscated but contains the primary malicious URL.

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=critical+reading+and+writing+for+senior+high+school+pdf
    • http://files.housingnwmiyouth.org/uploads/1/3/0/8/130874457/9944982.pdf
    • http://files.fencerowfinds.com/uploads/1/3/2/7/132740533/587244.pdf
    • http://files.fabinashelties.ca/uploads/1/3/1/4/131454560/72d85077e.pdf
    • http://files.kijasalon.com/uploads/1/3/0/8/130813913/tukujorobup.pdf
    • https://cdn.shopify.com/s/files/1/0434/9578/4600/files/zodiveguwekebawowom.pdf
    • https://cdn.shopify.com/s/files/1/0432/0106/9220/files/kinudupawojeli.pdf
    • https://cdn.shopify.com/s/files/1/0432/5530/0249/files/45450596021.pdf
    • https://cdn.shopify.com/s/files/1/0430/5960/9753/files/jl_audio_12w3v3._4.pdf
    • https://cdn.shopify.com/s/files/1/0429/1425/0905/files/8888873201.pdf
    • https://cdn.shopify.com/s/files/1/0430/6265/7177/files/kanuwimezudom.pdf
    • https://cdn.shopify.com/s/files/1/0435/2914/2426/files/amphiphilic_block_copolymers_self_assembly_and_applications.pdf
    • https://cdn.shopify.com/s/files/1/0435/8520/8483/files/mac_os_10._12_download.pdf
    • https://cdn.shopify.com/s/files/1/0435/6607/1971/files/genie_pro_88_manual.pdf
    • https://cdn.shopify.com/s/files/1/0440/3865/2069/files/zofutarisa.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_off00008781.bin
37671320c496f956762ef8f23f5d3677ccac19a8e8db317b8c60d6e13bd23df0
pdf-font-stream PDF embedded font (sfnt) at offset 0x8781 5416 bytes
font_01_sfnt_off000099fa.bin
f8feb01c51b00e0fde95b06ff6c2ee65f4486c68e82a5c94bf32fab1a8b94669
pdf-font-stream PDF embedded font (sfnt) at offset 0x99FA 10120 bytes