Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55e164b877129b1…

MALICIOUS

PDF

41.9 KB Created: 2020-08-30 04:05:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 277eb0364ae97168b5379bb931c68b04 SHA-1: c5be580df5cf30cc9d3c5ee014b69165852aad3f SHA-256: b55e164b877129b1c149025819206f8becc2298c30ff53bfd3bf098eda180d00
154 Risk Score

Malware Insights

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

The PDF contains embedded links that point to a known malicious redirector infrastructure, specifically 'ttraff.ru'. The document body, though heavily obfuscated, appears to be a lure related to a 'product rule and quotient rule worksheet'. The presence of numerous external PDF links, many hosted on 'static.usrfiles.com', suggests a link farm or SEO poisoning tactic to distribute the malicious content. The ML classifier strongly indicated maliciousness.

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=product+rule+and+quotient+rule+worksheet
    • https://static.usrfiles.com/ugd/b8c837_4d77737b94d848dcb854940b484f6258.pdf
    • https://static.usrfiles.com/ugd/7f16bd_0740de56124e43efa6c08ba6b2732f8a.pdf
    • https://static.usrfiles.com/ugd/b8c837_5eb25f9902e447c89147184e0b68948f.pdf
    • https://static.usrfiles.com/ugd/3ce946_bd28bb6c11434778a5c33e7d5f336627.pdf
    • https://static.usrfiles.com/ugd/ca32a8_9c4064328d3f46ff9b45fe4498e5b622.pdf
    • https://static.usrfiles.com/ugd/c345b0_82c558cc33434b68864e64df817c78bc.pdf
    • https://static.usrfiles.com/ugd/5b5da7_51f0163d1a6549e786b0bcc66649fafb.pdf
    • https://static.usrfiles.com/ugd/45fd81_ba4a646bf7fd4f20b1a0c7caafe35378.pdf
    • https://static.usrfiles.com/ugd/b8c837_0af06bc528704f598aac5c91b9f3948a.pdf
    • https://static.usrfiles.com/ugd/b8c837_6dbcdaef125f4c728bf5d08a2e289b9d.pdf
    • https://cdn.shopify.com/s/files/1/0447/2664/8986/files/migidodubudivifumuluzote.pdf
    • https://cdn.shopify.com/s/files/1/0438/5302/1334/files/cambridge_6_listening_test_3_answers.pdf
    • https://cdn.shopify.com/s/files/1/0436/3013/3406/files/fekigesiwufejizoteriz.pdf
    • https://cdn.shopify.com/s/files/1/0435/8098/1407/files/24283930816.pdf
    • https://cdn.shopify.com/s/files/1/0428/5415/4406/files/loseluxowumizenedu.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_off00006195.bin
59ff1aadf4677707944e9a800d2a7e1151bf147dfa8decfb2e47259dc9e3b33b
pdf-font-stream PDF embedded font (sfnt) at offset 0x6195 5312 bytes
font_01_sfnt_off000073a5.bin
617a037f71a497019779e197512f94bade0eb2749342e98d08f89f233ca94e7e
pdf-font-stream PDF embedded font (sfnt) at offset 0x73A5 12452 bytes