Malicious PDF — malware analysis report

Static analysis result for SHA-256 f916e3d9edeb5c03…

MALICIOUS

PDF

44.9 KB Created: 2020-08-08 05:52:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e2bf48c4348030f31508ea9a5e1e017b SHA-1: edc63cf69f132fa84923f6f15c234acf79208a2a SHA-256: f916e3d9edeb5c031d4236d047fe9c78f0e09a18eafbc6740461157a14bf3f34
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to Shopify domains, but one critical link directs to a known malicious redirector. The document body, though heavily obfuscated, contains text that appears to be a lure for an 'active learning book pdf'. The ML classifier strongly flagged this PDF as malicious. The primary attack pattern involves redirecting the user to malicious infrastructure via the embedded link.

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=active+learning+book+pdf
    • http://texone.waternexusbelgium.org/uploads/1/3/1/6/131606490/1813936.pdf
    • http://vepatofes.uhsbe.org/uploads/1/3/1/0/131069839/vapolotefizugeb.pdf
    • http://files.robertrichoux.com/uploads/1/3/1/6/131636589/5a46b3862c.pdf
    • https://cdn.shopify.com/s/files/1/0428/5209/0022/files/adventure_time_the_lich.pdf
    • https://cdn.shopify.com/s/files/1/0431/4166/0826/files/toribogixitejiguriwobimax.pdf
    • https://cdn.shopify.com/s/files/1/0437/6500/6494/files/95309491606.pdf
    • https://cdn.shopify.com/s/files/1/0431/7039/8372/files/kijilosozunefurokuzamago.pdf
    • https://cdn.shopify.com/s/files/1/0434/3863/7208/files/husqvarna_service_manual.pdf
    • https://cdn.shopify.com/s/files/1/0435/7239/6193/files/dutuzujefesol.pdf
    • https://cdn.shopify.com/s/files/1/0427/8052/4710/files/ginukiruranerevok.pdf
    • https://cdn.shopify.com/s/files/1/0427/8065/5775/files/750041984.pdf
    • https://cdn.shopify.com/s/files/1/0434/5207/2086/files/57093409315.pdf
    • https://cdn.shopify.com/s/files/1/0434/7818/8198/files/makkar_ielts_academic_writing_task_1_download_2020.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/5578033559.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_off00007354.bin
d80589f4f3473a2832e3863e5eb938db0472139a487b610b8c1a882ff9999f10
pdf-font-stream PDF embedded font (sfnt) at offset 0x7354 5396 bytes
font_01_sfnt_off000085c9.bin
5a2581f0fd72139a6600260594f7e7a7dc50b015eae4ab0f96bac4bc48ad5a13
pdf-font-stream PDF embedded font (sfnt) at offset 0x85C9 9736 bytes