Malicious PDF — malware analysis report

Static analysis result for SHA-256 5680a57d29ae7b11…

MALICIOUS

PDF

35.0 KB Created: 2020-08-12 22:49:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 28cd1847aa7f27db87ea46c3c7ca5096 SHA-1: b88122ad9b8e1c86326e99f349f88bf9ec000af3 SHA-256: 5680a57d29ae7b11d69713a78c66200ce0e30879626dc8df3ed7a3705f44236d
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to Shopify domains, but one critical link directs to a known malicious redirector. The document body, though heavily obfuscated, contains text related to a textbook and the malicious URL. The ML classifier strongly flagged this PDF as malicious. The primary attack pattern involves luring the user to a malicious site via a seemingly benign document.

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/wb?keyword=holt%20mcdougal%20world%20history%20online%20textbook%20pdf
    • http://files.justleeds.com/uploads/1/3/2/6/132681452/09b8f69e0a0bea7.pdf
    • http://barepivef.amsnorcal.com/uploads/1/3/1/3/131379578/0de15436e1b699a.pdf
    • http://wibof.lostlakefarmllc.com/uploads/1/3/1/4/131406437/5d63fb608bea19.pdf
    • http://files.jacquelineclewis.com/uploads/1/3/0/9/130969190/7356956.pdf
    • https://cdn.shopify.com/s/files/1/0429/2398/3001/files/movexefeni.pdf
    • https://cdn.shopify.com/s/files/1/0430/7389/6615/files/free_machine_embroidery_patterns.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/kuvesagapixunijibofalase.pdf
    • https://cdn.shopify.com/s/files/1/0430/6649/1042/files/jujopemaxu.pdf
    • https://cdn.shopify.com/s/files/1/0430/5344/9365/files/81718431916.pdf
    • https://cdn.shopify.com/s/files/1/0431/6954/6395/files/lamiludewanasilaluvuxofe.pdf
    • https://cdn.shopify.com/s/files/1/0435/5158/8507/files/kipusofaxutaw.pdf
    • https://cdn.shopify.com/s/files/1/0431/8520/9512/files/biomass_fuelled_power_plant.pdf
    • https://cdn.shopify.com/s/files/1/0432/3459/0878/files/2547030770.pdf
    • https://cdn.shopify.com/s/files/1/0429/2883/2675/files/ladijekafab.pdf
    • https://cdn.shopify.com/s/files/1/0428/7604/3423/files/pixuzuxado.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/52209678420.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_off000048bd.bin
855dce1d2500b4ceaac9630858ca0ae2cf8c901510340273288ba7e468270619
pdf-font-stream PDF embedded font (sfnt) at offset 0x48BD 5996 bytes
font_01_sfnt_off00005d16.bin
6eeec7ca99d3becc19a4e46df3cc8a539516fbd94e5502f946b9be69a9053457
pdf-font-stream PDF embedded font (sfnt) at offset 0x5D16 9984 bytes