Malicious PDF — malware analysis report

Static analysis result for SHA-256 28cda43188f504f8…

MALICIOUS

PDF

42.5 KB Created: 2020-08-31 07:16:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0fbb3cddad470c93830168f5ba8ef9fd SHA-1: 24d706f0bd0b19dbd5a1d52c189db4b342f2f080 SHA-256: 28cda43188f504f887768f3069373ce674ba1d1d1d629a7c08506dab95a7d975
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating it links to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the URL 'https://ttraff.club/wix?keyword=ejercicios+de+datos+agrupados+resueltos', which is identified as a malicious redirector. Additionally, the PDF exhibits characteristics of a link farm, with numerous embedded URLs pointing to external resources, including 'https://cdn.shopify.com/s/files/1/0433/0346/9221/files/tutagelelu.pdf'. This suggests a campaign leveraging SEO poisoning or phishing tactics.

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.club/wix?keyword=ejercicios+de+datos+agrupados+resueltos
    • https://cdn.shopify.com/s/files/1/0433/0346/9221/files/tutagelelu.pdf
    • https://cdn.shopify.com/s/files/1/0433/6504/0282/files/15748617972.pdf
    • https://cdn.shopify.com/s/files/1/0431/1928/0288/files/wonadugobozuruxofuper.pdf
    • https://cdn.shopify.com/s/files/1/0428/3269/1367/files/aprende_a_dibujar_paso_a_paso_chicas_manga.pdf
    • https://cdn.shopify.com/s/files/1/0432/8567/6192/files/zamirexawanewunugavomama.pdf
    • https://static.usrfiles.com/ugd/b8c837_ef897c7ff52441d5a2edf9cb7f65979b.pdf
    • https://static.usrfiles.com/ugd/b8c837_712dbd5c204d4b4094da27ff0538d1a6.pdf
    • https://static.usrfiles.com/ugd/b8c837_126fc4e8036b4a018433c4911e9352bf.pdf
    • https://static.usrfiles.com/ugd/b3bc21_079c2a33bf4b4aebb3b3b0495c60365b.pdf
    • https://static.usrfiles.com/ugd/7c3584_8a7c3017d6bb459180ae1e02966bdbd9.pdf
    • https://cdn.shopify.com/s/files/1/0428/8466/1407/files/40210893871.pdf
    • https://cdn.shopify.com/s/files/1/0447/0053/2889/files/almacenamiento_ptico_en_informatica.pdf
    • https://cdn.shopify.com/s/files/1/0429/3863/0300/files/44705906697.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_off00006431.bin
29256c2ac70f72b9acdddd6e2d91dd85046336059c5e649608de35347bc52c9b
pdf-font-stream PDF embedded font (sfnt) at offset 0x6431 5272 bytes
font_01_sfnt_off00007633.bin
387d12f15756a6241828f874419a573f2f0e659502a94f63abd546c24138b85a
pdf-font-stream PDF embedded font (sfnt) at offset 0x7633 11576 bytes