Malicious PDF — malware analysis report

Static analysis result for SHA-256 a543ed655bb0f2a8…

MALICIOUS

PDF

52.4 KB Created: 2020-08-29 23:32:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f1b9e8ba3da52d30df4a95aca73a2e84 SHA-1: 8a73583fc57e7ec7bc91e18678d9c25f6a7b3ceb SHA-256: a543ed655bb0f2a8c1f0e314148364bd03c0ddce2ba455883e5ee735f9c074af
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains embedded links, with one prominent URL pointing to a known malicious redirector. The ML classifier strongly indicates maliciousness. The document body, though heavily obfuscated, contains the same suspicious URL, suggesting a lure to a malicious site. The presence of numerous Shopify links, while mostly benign, forms part of a link farm strategy to improve SEO 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.ru/wix?keyword=atividades+recursos+naturais+6o+ano+ciencias+doc
    • https://cdn.shopify.com/s/files/1/0431/2816/0413/files/83598851916.pdf
    • https://cdn.shopify.com/s/files/1/0435/8383/2227/files/nemepomoxe.pdf
    • https://cdn.shopify.com/s/files/1/0433/9118/9157/files/47948562530.pdf
    • https://cdn.shopify.com/s/files/1/0428/4373/4182/files/dabasadejoxowig.pdf
    • https://cdn.shopify.com/s/files/1/0431/9870/9917/files/sensory_evaluation_techniques_download.pdf
    • https://cdn.shopify.com/s/files/1/0435/1708/3803/files/nezinudogajukejimomib.pdf
    • https://cdn.shopify.com/s/files/1/0434/0360/8214/files/99276412796.pdf
    • https://cdn.shopify.com/s/files/1/0430/2359/7725/files/kaliribat.pdf
    • https://cdn.shopify.com/s/files/1/0429/2309/8279/files/fake_marriage_certificate.pdf
    • https://cdn.shopify.com/s/files/1/0433/0913/8075/files/vevipevitopujaxozawenu.pdf
    • https://cdn.shopify.com/s/files/1/0431/5794/6519/files/37815991940.pdf
    • https://cdn.shopify.com/s/files/1/0437/1903/2987/files/86776925250.pdf
    • https://cdn.shopify.com/s/files/1/0433/1431/5422/files/3._5_frostburn.pdf
    • https://static.usrfiles.com/ugd/b8c837_0e7bc79e0ba34dc097d6464112ca8e8f.pdf
    • https://static.usrfiles.com/ugd/dfb5f8_f9a4d82f97df47b98b6558ffce61cf12.pdf
    • https://static.usrfiles.com/ugd/b8c837_a357a50928244d5bb6def5c10414f7e1.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_off000083ab.bin
b60c53f80b54f36db378fd4ff0f59756844715b375b3e0fe500a32e99f0f19d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x83AB 5104 bytes
font_01_sfnt_off00009511.bin
ee61f4e0a51ca99feb866cedee85d69cbaa88bd69629644019e9cfe3d4670774
pdf-font-stream PDF embedded font (sfnt) at offset 0x9511 15624 bytes