Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5e993cc8cf61187…

MALICIOUS

PDF

51.1 KB Created: 2020-08-15 00:05:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fc78aae1bb43af6d540c48f5516fecf9 SHA-1: 78cb702c7d07f983dc7d503999c71f11bee05154 SHA-256: a5e993cc8cf6118718b90abc4f5bd3051e82d8533d5da8e2d12db10ee950f630
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1200 Hardware Add-in T1059.001 PowerShell

The PDF contains a link farm designed to appear as legitimate PDF downloads, but the primary link redirects to a known malicious redirector. The ML classifier strongly indicated maliciousness, and the PDF structure itself is indicative of SEO spam tactics to distribute malicious links. No scripts were extracted, but the embedded links are sufficient to classify the attack pattern.

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/pify?keyword=bearing+capacity+of+soil+test+pdf
    • http://files.saintalphonsusschool.org/uploads/1/3/1/8/131857071/b41fba5.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/zenafepejeviwasi.pdf
    • https://cdn.shopify.com/s/files/1/0431/3471/4017/files/tevebapubevunoxep.pdf
    • https://cdn.shopify.com/s/files/1/0429/3125/7510/files/energia_biomassa_vantagens_e_desvantagens.pdf
    • https://cdn.shopify.com/s/files/1/0431/9268/0605/files/kirkpatrick_model_of_curriculum_evaluation.pdf
    • https://cdn.shopify.com/s/files/1/0428/2132/0870/files/lidalemetozepufu.pdf
    • https://cdn.shopify.com/s/files/1/0427/4244/8295/files/31496908062.pdf
    • https://cdn.shopify.com/s/files/1/0437/8460/1761/files/28617138230.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/nomevorijodasulalo.pdf
    • https://cdn.shopify.com/s/files/1/0434/6006/7480/files/familowu.pdf
    • https://cdn.shopify.com/s/files/1/0430/9244/3303/files/ano_ang_panitikang_pilipino.pdf
    • https://cdn.shopify.com/s/files/1/0429/9997/1999/files/26059626870.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_off0000657b.bin
2e78bd2252fe03a02aa858c9befb402d5dc2eea53346c2b10472f932a6990f64
pdf-font-stream PDF embedded font (sfnt) at offset 0x657B 5476 bytes
font_01_sfnt_off00007827.bin
bae51265f9dbaad2c351771562535c04a2ca19092c29664bc23d4a0dd8045291
pdf-font-stream PDF embedded font (sfnt) at offset 0x7827 15856 bytes
font_02_sfnt_off0000ab0f.bin
52db30b66cfb76898988bc7c6ed152514c301740808ab95bec9c68e49df23550
pdf-font-stream PDF embedded font (sfnt) at offset 0xAB0F 16036 bytes