Malicious PDF — malware analysis report

Static analysis result for SHA-256 c79219e639c4cd88…

MALICIOUS

PDF

33.2 KB Created: 2020-08-28 08:51:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1799ce64c94fa6675195b8d4de6065b7 SHA-1: ae0ea7d187d937baa37e53635d360293b2dbb1a5 SHA-256: c79219e639c4cd88e4e6cfdbfd405a5919d3c8450a931a9d00fd3d652f6407e8
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

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 'acls post test answer key 2018 pdf' and the malicious URL, suggesting a lure to trick users into clicking the link. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious redirector attack pattern.

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=acls+post+test+answer+key+2018+pdf
    • http://lumaditob.caribbeanshadeproducts.com/uploads/1/3/1/4/131407435/rirekadike.pdf
    • http://files.fernandojimenezphoto.com/uploads/1/3/1/3/131382217/3010862.pdf
    • http://files.lindsaywhitemusic.com/uploads/1/3/0/7/130776433/meretibo_pojogu_gumumamatov_dusomajuludaxu.pdf
    • http://files.ultratech-electronics.com/uploads/1/3/2/8/132814980/ginofabas.pdf
    • http://files.kundaliniyogayorkshire.org/uploads/1/3/2/6/132682210/2108046.pdf
    • https://cdn.shopify.com/s/files/1/0437/7965/3789/files/4384453826.pdf
    • https://cdn.shopify.com/s/files/1/0430/8071/2346/files/zezijiw.pdf
    • https://cdn.shopify.com/s/files/1/0430/1311/1961/files/fun_easy_brain_teasers_with_answers.pdf
    • https://cdn.shopify.com/s/files/1/0427/5562/1031/files/zoguxexawajodidebuw.pdf
    • https://cdn.shopify.com/s/files/1/0427/6027/4087/files/94806282870.pdf
    • https://cdn.shopify.com/s/files/1/0427/4218/6150/files/6553876024.pdf
    • https://cdn.shopify.com/s/files/1/0428/1742/1479/files/54271978165.pdf
    • https://cdn.shopify.com/s/files/1/0432/2725/0848/files/59148919789.pdf
    • https://cdn.shopify.com/s/files/1/0435/3222/2615/files/ikea_catalogue_uk.pdf
    • https://cdn.shopify.com/s/files/1/0431/1570/8580/files/jagusokuruti.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_off000044cc.bin
54af6d7626c8ac2a94ca4eb4bdf916bdb764dc674ad88f6ec12362f488732375
pdf-font-stream PDF embedded font (sfnt) at offset 0x44CC 5916 bytes
font_01_sfnt_off00005914.bin
b091fcb3d74433e7a74c6fec5225404ce690b165006f6dc94dacc25191e11751
pdf-font-stream PDF embedded font (sfnt) at offset 0x5914 9036 bytes