Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a1fc9dc81bfa9d7…

MALICIOUS

PDF

41.8 KB Created: 2020-08-09 01:04:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 12108ef21213e1c8c0d6d73f991a5a6a SHA-1: 59c79c5a6bf9a61af10a73a31cd244d19e95873c SHA-256: 4a1fc9dc81bfa9d73a54b373ffd8b5f2994af2d9b0d32ab31b5ee989f2b49a65
152 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and contains numerous embedded links. One critical heuristic indicates that the PDF links to known malicious redirector infrastructure, specifically 'https://ttraff.ru/pify?keyword=srs+for+asset+management+system+pdf'. Another critical heuristic identifies it as a PDF link farm, with many external links, some pointing to benign Shopify URLs and others to unknown domains. The document body contains garbled text but includes the same suspicious URL and several other PDF links.

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=srs+for+asset+management+system+pdf
    • http://files.poetatrainingcenter.com/uploads/1/3/1/1/131164048/a6e8f.pdf
    • http://files.fredabedi.com/uploads/1/3/1/3/131398573/kegizeko.pdf
    • http://files.michellehutchinsonart.com/uploads/1/3/0/8/130873794/somudavemulafosusuwu.pdf
    • http://files.tcnjcogdevlab.com/uploads/1/3/1/3/131380687/somikod.pdf
    • https://cdn.shopify.com/s/files/1/0433/2044/3045/files/nururedovifigip.pdf
    • https://cdn.shopify.com/s/files/1/0438/4541/9165/files/anderson_multivariate_statistical_analysis.pdf
    • https://cdn.shopify.com/s/files/1/0433/2371/9845/files/nudopegidewumako.pdf
    • https://cdn.shopify.com/s/files/1/0432/5389/1232/files/kesidemib.pdf
    • https://cdn.shopify.com/s/files/1/0433/8604/4570/files/47762687898.pdf
    • https://cdn.shopify.com/s/files/1/0433/4590/3781/files/25189273498.pdf
    • https://cdn.shopify.com/s/files/1/0429/7857/4490/files/vulemulefalukar.pdf
    • https://cdn.shopify.com/s/files/1/0428/8937/9993/files/sozawama.pdf
    • https://cdn.shopify.com/s/files/1/0432/4455/2354/files/sojiruleselupom.pdf
    • https://cdn.shopify.com/s/files/1/0435/1823/0688/files/11156378936.pdf
    • https://cdn.shopify.com/s/files/1/0433/1926/3397/files/zelefakobani.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_off000063e0.bin
070628d8bb57d2bab03eef81024950e563b0b18d9c339fd1deaf5d7a3b1531f6
pdf-font-stream PDF embedded font (sfnt) at offset 0x63E0 5532 bytes
font_01_sfnt_off0000769e.bin
2f26ba13973605a0d62ec12a74744b692c103ca56ce6a962ff47e26493ff117b
pdf-font-stream PDF embedded font (sfnt) at offset 0x769E 10664 bytes