Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e505f652147bdec…

MALICIOUS

PDF

40.8 KB Created: 2020-08-29 22:55:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 539f8a25cabf943d1b6e35ea9bafe3a4 SHA-1: 1b14f39296bcf424759868af46e91408016bb329 SHA-256: 6e505f652147bdec88d758fe4beb62f40b50d718c87dc0041005c1af4e9d1b6f
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many pointing to seemingly benign PDF files, but one critical link directs to a known malicious redirector. This suggests a tactic to obscure malicious intent by burying it within a large collection of links, potentially to evade detection or to appear as a legitimate link farm. 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/wix?keyword=step+up+to+writing+printables
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b8c837_2b14eb682f704021adc5dfbf9910e8c5.pdf
    • https://static.usrfiles.com/ugd/b8c837_6cbaf4432a3240aebeb8cc751c0e4c84.pdf
    • https://static.usrfiles.com/ugd/44b221_941c898e4c7b4721893bdc935bd00bb5.pdf
    • https://static.usrfiles.com/ugd/b8c837_ba3326000c4c431b9463f4676d64e347.pdf
    • https://cdn.shopify.com/s/files/1/0437/0428/7383/files/top_down_and_bottom_up_budgeting_in_project_management.pdf
    • https://cdn.shopify.com/s/files/1/0432/8616/7702/files/public_health_act_and_policies_in_zambia.pdf
    • https://cdn.shopify.com/s/files/1/0464/7691/8934/files/joled.pdf
    • https://cdn.shopify.com/s/files/1/0431/8117/9037/files/luduvuka.pdf
    • https://cdn.shopify.com/s/files/1/0437/8542/0949/files/voletabazi.pdf
    • https://cdn.shopify.com/s/files/1/0437/0087/9510/files/77330250673.pdf
    • https://cdn.shopify.com/s/files/1/0451/1550/6853/files/action_bar_text_align_center_android.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_off000061b0.bin
87634e52941d0ac0d6c95c23f3ccd335024460689a07e6dac0ce0444db018966
pdf-font-stream PDF embedded font (sfnt) at offset 0x61B0 5324 bytes
font_01_sfnt_off000073e8.bin
76d7d21f83be2dfb01aac2fec9878c0f8035d4444a3e9bf1a5d99dc7d558d819
pdf-font-stream PDF embedded font (sfnt) at offset 0x73E8 10188 bytes