Malicious PDF — malware analysis report

Static analysis result for SHA-256 757d5d7abb09170c…

MALICIOUS

PDF

35.3 KB Created: 2020-08-14 06:44:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f82ee31aa6aeba3a6a55fbb2f9405ea2 SHA-1: 533394b1d82f016dcb343d2ba9085451afa3a580 SHA-256: 757d5d7abb09170c8b9bf067e359a517945fd78dc11161612d6ba4ccdb88f304
154 Risk Score

Malware Insights

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

The PDF document contains embedded links that redirect to malicious infrastructure, specifically a link farm designed to host numerous PDFs. The document body, though partially corrupted, contains text related to a USPS change of address form, serving as a lure. The presence of a malicious redirector URL and the ML classifier flagging it as malicious strongly indicate a phishing or redirection attack.

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.cc/pify?keyword=free+usps+change+of+address+form+pdf
    • http://files.llaart.org/uploads/1/3/1/4/131483002/89dca.pdf
    • http://nunilur.northernfitness.net/uploads/1/3/0/7/130739227/2503783.pdf
    • http://files.girlpushespaint.com/uploads/1/3/1/6/131607600/jiderilanowopifur.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0434/4909/0200/files/filesystem_move_node.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/81603963226.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/12509012650.pdf
    • https://cdn.shopify.com/s/files/1/0429/3158/5180/files/xowibinirodatutegavemix.pdf
    • https://cdn.shopify.com/s/files/1/0429/7791/9129/files/foxofazadanuwumozigigovo.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/66048758492.pdf
    • https://cdn.shopify.com/s/files/1/0439/2088/3880/files/19779433321.pdf
    • https://cdn.shopify.com/s/files/1/0437/6556/3549/files/9034428001.pdf
    • https://cdn.shopify.com/s/files/1/0434/6806/2872/files/73509225679.pdf
    • https://cdn.shopify.com/s/files/1/0428/0261/0335/files/rokizizenuvijuxekejadawe.pdf
    • https://cdn.shopify.com/s/files/1/0428/5261/4311/files/toxepilejedejegeralijuli.pdf
    • https://cdn.shopify.com/s/files/1/0433/8266/9461/files/fosibusewojujon.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_off00004b08.bin
23eaa106cd71e536dc2101bba57637fe2a3497788e973524cb2b141945bd1872
pdf-font-stream PDF embedded font (sfnt) at offset 0x4B08 5492 bytes
font_01_sfnt_off00005d90.bin
e97f09d61cde010dadf7c9f4d2d6ae3626fc41c8be7de9259ec6f77f986f589e
pdf-font-stream PDF embedded font (sfnt) at offset 0x5D90 10076 bytes