Malicious PDF — malware analysis report

Static analysis result for SHA-256 736edb1eb81726e8…

MALICIOUS

PDF

44.1 KB Created: 2020-08-07 16:12:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d0dfd49e2e44271cbed7f97477603ed4 SHA-1: 89f3dba1ae19a4d325b59b50dbeaaeb27f3de88c SHA-256: 736edb1eb81726e89e49e2048ce85a32bca2971a8b9929b7297983d7fadd1595
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a lure related to reducing file size, but the primary malicious activity is indicated by the PDF_MALICIOUS_REDIRECTOR_LINK and PDF_SEO_LINK_FARM heuristics. The sample redirects to a malicious URL and hosts a large number of external PDF links, suggesting a campaign to manipulate search results or distribute further malicious content. The ML_NYX_PDF_MALICIOUS heuristic strongly supports the malicious classification.

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=reduce+pdf+file+size+macbook
    • http://files.adventuresav.com/uploads/1/3/1/8/131856409/6084706.pdf
    • http://files.buy-ephedrine-uk.com/uploads/1/3/1/4/131438113/833393.pdf
    • http://files.proseandcommas.org/uploads/1/3/1/0/131071082/6343639.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/tuwupijisunuxavupo.pdf
    • https://cdn.shopify.com/s/files/1/0429/1241/5907/files/zirelikigubulo.pdf
    • https://cdn.shopify.com/s/files/1/0433/7228/2008/files/concept_of_marketing_information_system.pdf
    • https://cdn.shopify.com/s/files/1/0433/9580/9431/files/punemopegugisumeveve.pdf
    • https://cdn.shopify.com/s/files/1/0427/7701/8524/files/87369234032.pdf
    • https://cdn.shopify.com/s/files/1/0432/6057/5912/files/begakosavawepogekazev.pdf
    • https://cdn.shopify.com/s/files/1/0433/7015/2088/files/xudesibomitokofo.pdf
    • https://cdn.shopify.com/s/files/1/0440/7328/7830/files/58885079358.pdf
    • https://cdn.shopify.com/s/files/1/0447/7802/9213/files/afr_2020.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005f65.bin
aaa60f7778d3046cb674e0488dcd196e309e3875acb787c1851816d7b2729b74
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F65 5164 bytes
font_01_sfnt_off000070fe.bin
5cc0daee50dd3e13106979f8f899684bed3b6a6d162b38e52592d2563c78fe0d
pdf-font-stream PDF embedded font (sfnt) at offset 0x70FE 10784 bytes
font_02_sfnt_off0000959d.bin
9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2
pdf-font-stream PDF embedded font (sfnt) at offset 0x959D 4324 bytes