Malicious PDF — malware analysis report

Static analysis result for SHA-256 8739a442bb582afa…

MALICIOUS

PDF

46.9 KB Created: 2020-08-05 06:29:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 140d268b7404f2e30cba24d21425ca64 SHA-1: 1ae619213ddb290e06394c7d981f84c4b921d911 SHA-256: 8739a442bb582afa5bf2c60609b93e36d39208df8d5fe1f027b097b7dfb480d3
152 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as a free download, aiming to trick users into clicking it. The ML classifier strongly indicated maliciousness, and the presence of numerous external links, many pointing to Shopify, suggests a link farm or SEO manipulation tactic to distribute the malicious URL. The document body itself contains the lure text and the malicious URL.

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.com/pify?keyword=precalculus+book+pdf+download
    • http://files.tcapaving.com/uploads/1/3/2/3/132303261/9586986.pdf
    • http://putog.verisoftgroup.com/uploads/1/3/0/7/130738836/sinogojixarajira.pdf
    • http://files.maddiebooks.com/uploads/1/3/2/6/132682792/zesatawuvemu_zofabaxalogezaj_mavujenatijit.pdf
    • http://files.imagesbylesrigby.com/uploads/1/3/1/4/131455621/66425c63f2b.pdf
    • https://cdn.shopify.com/s/files/1/0435/7577/1304/files/69110816275.pdf
    • https://cdn.shopify.com/s/files/1/0434/0426/3585/files/37718361502.pdf
    • https://cdn.shopify.com/s/files/1/0436/3039/5552/files/betty_lukens_teacher_s_manual.pdf
    • https://cdn.shopify.com/s/files/1/0429/7208/6423/files/11969109577.pdf
    • https://cdn.shopify.com/s/files/1/0431/6761/3087/files/nutrition_free_download.pdf
    • https://cdn.shopify.com/s/files/1/0432/8269/4312/files/32180531143.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/84312174386.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/82505274200.pdf
    • https://cdn.shopify.com/s/files/1/0433/5956/8027/files/56929030562.pdf
    • https://cdn.shopify.com/s/files/1/0433/2571/8678/files/latudeguledexiweduteroda.pdf
    • https://cdn.shopify.com/s/files/1/0433/9076/3175/files/fasituw.pdf
    • https://cdn.shopify.com/s/files/1/0437/8161/9861/files/axis_allies_d_day_rules.pdf
    • https://cdn.shopify.com/s/files/1/0433/3489/3721/files/13339652650.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_off00007a31.bin
ca92dc919acb5d918b5e5855c1ba92b203b2a727ee18a4d80c4453636bf6ecd6
pdf-font-stream PDF embedded font (sfnt) at offset 0x7A31 5444 bytes
font_01_sfnt_off00008cd1.bin
6e3b4759f53aef5e92c308ad0ba29cec29624fd0dbde20a3be9b45c48db3bbe9
pdf-font-stream PDF embedded font (sfnt) at offset 0x8CD1 9928 bytes