Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f528ca3ac29dd21…

MALICIOUS

PDF

82.3 KB Created: 2020-07-30 03:31:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dd18717914a5fb0c04df1e537a9d0f33 SHA-1: 844cfc9740ac83556923b18940f68c9c5b5457ae SHA-256: 8f528ca3ac29dd21cad64f6a646ca1a6a3f609535928a758c8162861f45560f1
154 Risk Score

Malware Insights

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

The PDF contains multiple embedded links, with one specifically pointing to a known malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool sometimes used to create malicious PDFs. The primary attack vector appears to be luring the user to click on the malicious link, likely leading to a phishing or scam page.

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=tipos+de+aparejos+de+ladrillo+pdf
    • http://files.jtdudrow.com/uploads/1/3/0/7/130776757/2067405.pdf
    • http://files.mertech.co.uk/uploads/1/3/1/4/131453348/gekovoweju.pdf
    • http://files.masterj.org/uploads/1/3/0/7/130775505/6380592.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/89349082521.pdf
    • https://cdn.shopify.com/s/files/1/0431/2327/7973/files/32856339244.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/xokuwunojuvilil.pdf
    • https://cdn.shopify.com/s/files/1/0431/0512/4503/files/90834697066.pdf
    • https://cdn.shopify.com/s/files/1/0433/7857/3464/files/nemuva.pdf
    • https://cdn.shopify.com/s/files/1/0435/3199/3242/files/bufubaram.pdf
    • https://cdn.shopify.com/s/files/1/0428/6794/9724/files/zomilokukelem.pdf
    • https://cdn.shopify.com/s/files/1/0429/6137/1290/files/lemopipax.pdf
    • https://cdn.shopify.com/s/files/1/0432/9812/8036/files/425028802.pdf
    • https://cdn.shopify.com/s/files/1/0427/8029/5334/files/82369991298.pdf
    • https://cdn.shopify.com/s/files/1/0429/3351/8489/files/94410890878.pdf
    • https://cdn.shopify.com/s/files/1/0431/5480/0797/files/57685989425.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa73.bin
a15f5a690000a59fd1d6acd8a84347289ed07603b7540e62bb0f38f961135c49
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA73 1720 bytes
font_01_sfnt_off000102e6.bin
afde24706fe3dd79ee584ba780e2f7bb5f5e618b112c68a329306fd61698a5e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x102E6 4664 bytes
font_02_sfnt_off000112c9.bin
8f5877878582e14a031638ac8d3312ffb009f11109e1b823e04850071261ff09
pdf-font-stream PDF embedded font (sfnt) at offset 0x112C9 12256 bytes