Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bf6ecaa048e334d…

MALICIOUS

PDF

42.2 KB Created: 2020-08-25 08:59:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d8e27bd78987828336e09df2596b3945 SHA-1: e6d7b3e6d6526942fe803733dafa5a28ce314667 SHA-256: 4bf6ecaa048e334d2c21fd25573d2445c164efa6b05e6971d2531e6021de841c
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a redirector service (ttraff.ru) known for malicious activity. The document body, though heavily obfuscated, contains text related to educational materials, suggesting a lure to trick users into clicking the malicious links. The ML classifier also 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/pify?keyword=grade+9+applied+science+textbook+pdf
    • http://files.eunjukang.net/uploads/1/3/1/4/131437595/1043432.pdf
    • http://files.hartfordfederated.org/uploads/1/3/0/8/130874058/1889149.pdf
    • http://vegep.merelmarytheblog.com/uploads/1/3/1/4/131437601/5940641.pdf
    • http://files.articulatetree.com/uploads/1/3/1/4/131453560/3299548.pdf
    • https://cdn.shopify.com/s/files/1/0437/1048/0533/files/field_hockey_stick_guidelines.pdf
    • https://cdn.shopify.com/s/files/1/0459/2258/2679/files/vemazizal.pdf
    • https://cdn.shopify.com/s/files/1/0431/0745/1042/files/ncaa_basketball_uniforms_2018.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/tujekozovazufurujujazer.pdf
    • https://cdn.shopify.com/s/files/1/0437/2132/6742/files/doburomebofutigoberi.pdf
    • https://cdn.shopify.com/s/files/1/0432/2436/7262/files/52690223136.pdf
    • https://cdn.shopify.com/s/files/1/0435/2121/2570/files/free_vpn_server.pdf
    • https://cdn.shopify.com/s/files/1/0433/4164/3928/files/15473546099.pdf
    • https://cdn.shopify.com/s/files/1/0434/3683/4981/files/31307545850.pdf
    • https://cdn.shopify.com/s/files/1/0430/6327/9767/files/systemic_inflammatory_response_syndrome_guidelines.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_off000063eb.bin
b81b9047e6476c3162286a26e1e2ba18efb7049750c2f2acd5fdf71ac6d1b7e7
pdf-font-stream PDF embedded font (sfnt) at offset 0x63EB 5608 bytes
font_01_sfnt_off00007713.bin
0a36e1e26b0368994775a73abfc67741882c32e51e1f3abb351d2e5933045980
pdf-font-stream PDF embedded font (sfnt) at offset 0x7713 10416 bytes