Malicious PDF — malware analysis report

Static analysis result for SHA-256 a85b157c8e8a65ad…

MALICIOUS

PDF

42.2 KB Created: 2020-08-12 17:11:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 09708bfe735a249f667cfc3b8ca9cc8c SHA-1: 801341ae8cdad11efadb5ff2904d6f7530c826f6 SHA-256: a85b157c8e8a65adb00998864e252a935f4f3e930a6a4bc0ee4d3e72fc7e85a9
152 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as a free Arduino tutorial. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK confirms this, and the ML classifier strongly indicates maliciousness. The document body contains the lure text and the malicious URL, alongside a large number of other URLs, 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.com/wb?keyword=arduino%20tutorial%20pdf%20free
    • http://files.bikeleelanau.com/uploads/1/3/2/6/132681812/tibodewopo_babilaborepixed.pdf
    • http://files.carchethealing.com/uploads/1/3/1/3/131398022/pezagiwep-mulugewedudiri.pdf
    • http://files.rdadivenet.com/uploads/1/3/1/6/131637043/8612727.pdf
    • https://cdn.shopify.com/s/files/1/0429/6923/5619/files/88844805354.pdf
    • https://cdn.shopify.com/s/files/1/0437/6467/8807/files/definisi_atonia_uteri.pdf
    • https://cdn.shopify.com/s/files/1/0430/4509/3533/files/veletogirenoz.pdf
    • https://cdn.shopify.com/s/files/1/0430/9703/0805/files/dobovabigelopatatosada.pdf
    • https://cdn.shopify.com/s/files/1/0434/8523/3304/files/62633788270.pdf
    • https://cdn.shopify.com/s/files/1/0430/3110/1603/files/pdf_to_word_converter_direct_download.pdf
    • https://cdn.shopify.com/s/files/1/0432/2131/9837/files/76796900999.pdf
    • https://cdn.shopify.com/s/files/1/0434/6436/0100/files/69955941308.pdf
    • https://cdn.shopify.com/s/files/1/0431/1239/9010/files/fovonez.pdf
    • https://cdn.shopify.com/s/files/1/0430/4571/6129/files/44915330207.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_off00005b92.bin
dfda12130b119c9f4d0c3a26dcd635d2fd4224f17857b65c4b5670d4dbfa441e
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B92 4728 bytes
font_01_sfnt_off00006baa.bin
a2c84f518e1222a16f01fe027c257a17436a86978725f822790d6e81d85de510
pdf-font-stream PDF embedded font (sfnt) at offset 0x6BAA 10084 bytes
font_02_sfnt_off00008e2d.bin
4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3
pdf-font-stream PDF embedded font (sfnt) at offset 0x8E2D 4324 bytes