Malicious PDF — malware analysis report

Static analysis result for SHA-256 31ea1fee401c5a91…

MALICIOUS

PDF

59.6 KB Created: 2020-08-15 04:48:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0e02df53851df3f105cfe15c11a3917a SHA-1: a6c9ae10f569efb1cc0c66ff12f51abc36dbec48 SHA-256: 31ea1fee401c5a91a8c68535ddb1befd323e1d8a13a362a677321e7544f2b586
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, with numerous embedded URLs pointing to external PDF files. The primary malicious URL, https://ttraff.ru/wb?keyword=velocidad%20de%20reaccion%20pdf, is identified as a redirector to malicious infrastructure. The ML classifier strongly supports the malicious nature of this PDF. No scripts were extracted, and the document body is heavily obfuscated, making it difficult to determine the exact user-facing lure.

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/wb?keyword=velocidad%20de%20reaccion%20pdf
    • http://kavitu.hackettville.com/uploads/1/3/1/4/131482975/d3ade.pdf
    • http://files.cohncentric.com/uploads/1/3/1/4/131437380/2459847.pdf
    • http://jegenoko.alliancebravesbaseball.com/uploads/1/3/1/3/131383791/wumulibem.pdf
    • http://files.highergearcoaching.com/uploads/1/3/2/6/132682030/9895675.pdf
    • https://cdn.shopify.com/s/files/1/0435/4434/6792/files/rodubufiv.pdf
    • https://cdn.shopify.com/s/files/1/0431/2468/7014/files/drop_primary_key.pdf
    • https://cdn.shopify.com/s/files/1/0436/6961/8841/files/teworopowuj.pdf
    • https://cdn.shopify.com/s/files/1/0434/1674/8188/files/83565138096.pdf
    • https://cdn.shopify.com/s/files/1/0448/7554/6791/files/bteb_result_2020_6th_semester_download.pdf
    • https://cdn.shopify.com/s/files/1/0432/1997/6350/files/metodos_de_abstinencia_periodica.pdf
    • https://cdn.shopify.com/s/files/1/0434/5951/0424/files/ashoka_chakravarthy_telugu_songs.pdf
    • https://cdn.shopify.com/s/files/1/0433/8896/0933/files/20333580376.pdf
    • https://cdn.shopify.com/s/files/1/0436/3550/7358/files/zumujekupeveveze.pdf
    • https://cdn.shopify.com/s/files/1/0431/8442/3073/files/orthographe_francais.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_off0000877f.bin
3c2fc2b58ca16659b4aec438b96d1e309652333926c8948fba0e2160a3a2c4ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x877F 4936 bytes
font_01_sfnt_off0000984d.bin
96e671a9880e42732eeea85e071e72cdd19518b2c133b8e60ffca33de2cdd137
pdf-font-stream PDF embedded font (sfnt) at offset 0x984D 16376 bytes
font_02_sfnt_off0000ca54.bin
a45b3a977511534bd8b8ba41ae8fd929e4e87281fd7e6afab076c615d4866160
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA54 16300 bytes