Malicious PDF — malware analysis report

Static analysis result for SHA-256 833d2520ce3c9c76…

MALICIOUS

PDF

42.7 KB Created: 2020-08-31 06:17:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a8d02f74eb95cbd923e79959742290e5 SHA-1: 7cf972d740e4aee6977ba936025d213e77d767a1 SHA-256: 833d2520ce3c9c768d653938827ab21bae3f87902f87cb5106f846aa6aaaa6da
162 Risk Score

Malware Insights

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

The PDF file contains embedded links, one of which, https://ttraff.ru/wix?keyword=letter+of+complaint+useful+phrases, is flagged as a malicious redirector. The document body, though heavily obfuscated, contains text suggesting it is a lure for 'letter of complaint useful phrases', aligning with phishing tactics. The presence of numerous external PDF links further indicates a link farm, often used to distribute malicious content or for SEO manipulation to improve the ranking of malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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=letter+of+complaint+useful+phrases
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/aef5b7_3b5c61ca5f4f415592eb710360d1c32c.pdf
    • https://static.usrfiles.com/ugd/b8c837_4373865ff713443e9c4123674c41c7e9.pdf
    • https://static.usrfiles.com/ugd/97634b_ba4539a8f6194c71b47c66605fc91eae.pdf
    • https://static.usrfiles.com/ugd/10b11f_8b252040f8794d3890933bd06c6723c0.pdf
    • https://static.usrfiles.com/ugd/cc03df_a07ecbd3e4e349998ce86ca2125b23c2.pdf
    • https://cdn.shopify.com/s/files/1/0435/5896/1320/files/9863695971.pdf
    • https://cdn.shopify.com/s/files/1/0440/2796/9686/files/22036849728.pdf
    • https://cdn.shopify.com/s/files/1/0429/5042/6787/files/99810243233.pdf
    • https://cdn.shopify.com/s/files/1/0433/8103/1064/files/jonanaraxo.pdf
    • https://cdn.shopify.com/s/files/1/0433/9721/8467/files/vizedukoxejetifevugu.pdf
    • https://cdn.shopify.com/s/files/1/0434/7274/8710/files/warhammer_40k_tyranids_8th_codex.pdf
    • https://cdn.shopify.com/s/files/1/0427/4490/5884/files/39019565114.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_off000069ff.bin
0165a7acfa2d588e7564c2dac25d4cbfb7f17f7bc13f2d8aff141cc2a41d4056
pdf-font-stream PDF embedded font (sfnt) at offset 0x69FF 5196 bytes
font_01_sfnt_off00007b7f.bin
2ceb4ba9bcc86d0eadba960c739fdc05ce731bcdfd9c06c1f2aea6023f245a94
pdf-font-stream PDF embedded font (sfnt) at offset 0x7B7F 10192 bytes