Malicious PDF — malware analysis report

Static analysis result for SHA-256 091cfab386604d15…

MALICIOUS

PDF

43.1 KB Created: 2020-08-15 10:43:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c1c7ef7677c3ef2862aac16a5343d7da SHA-1: 625dbd0a10ed65f6e6118f8e967dc6827b5a27fb SHA-256: 091cfab386604d155e9ba4493dc41ef2116b3cf6f64887914e247abb0af15baa
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link to a redirector URL, which is a strong indicator of malicious intent, likely to lead users to a phishing or malware download site. The document body, though heavily obfuscated, contains keywords related to 'tutorial google classroom 2019 pdf', suggesting a lure to trick users into clicking the malicious link. The presence of numerous external PDF links, many pointing to benign Shopify URLs, suggests a link farm or SEO manipulation tactic to improve the ranking of the malicious redirector.

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.com/wb?keyword=tutorial%20google%20classroom%202019%20pdf
    • http://files.fragmentapp.info/uploads/1/3/1/4/131454567/wediduvu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0437/3757/9674/files/new_venture_gear_3500_transmission.pdf
    • https://cdn.shopify.com/s/files/1/0435/7108/5475/files/brainstorming_exercises.pdf
    • https://cdn.shopify.com/s/files/1/0431/0210/9856/files/51387286328.pdf
    • https://cdn.shopify.com/s/files/1/0429/5183/5801/files/psychology_8th_edition_gleitman.pdf
    • https://cdn.shopify.com/s/files/1/0429/6753/1673/files/zedikebibuvo.pdf
    • https://cdn.shopify.com/s/files/1/0431/2255/7082/files/81804473350.pdf
    • https://cdn.shopify.com/s/files/1/0431/5847/0816/files/phoneclaim_sprint_uploader.pdf
    • https://cdn.shopify.com/s/files/1/0434/5564/3813/files/jusenajapadowizuni.pdf
    • https://cdn.shopify.com/s/files/1/0434/0737/6546/files/axum_obelisk.pdf
    • https://cdn.shopify.com/s/files/1/0455/3906/6021/files/xukepalonav.pdf
    • https://cdn.shopify.com/s/files/1/0440/2806/7990/files/72487301984.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006830.bin
d2cce78836013783ed13672d0798764186eb8739b98ba31e69216ca8994a06d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x6830 5908 bytes
font_01_sfnt_off00007c3a.bin
89f482bf169942b8d6c600e2686d5a15dc40cffbee70fe02d18faedff5ee03bb
pdf-font-stream PDF embedded font (sfnt) at offset 0x7C3A 10440 bytes