Malicious PDF — malware analysis report

Static analysis result for SHA-256 d7ce555e98bf6250…

MALICIOUS

PDF

44.5 KB Created: 2020-08-16 17:10:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e388d518cdba522959a871677539ee67 SHA-1: 6db83b840abdd1dc9209ec0a0fdea49fa82b93dc SHA-256: d7ce555e98bf625044297179be2b3749b2bd788b692c9122b685147b71962710
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains a deceptive link presented as an 'Army ASVAB practice test' which redirects to a malicious URL. This indicates a phishing or social engineering attack aimed at tricking users into visiting compromised sites. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous embedded links to external PDFs, many hosted on Shopify, suggests a link farm designed to obscure the final malicious destination.

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/pify?keyword=army+asvab+practice+test
    • http://files.christopherhale.net/uploads/1/3/2/8/132814241/lipuvoxagizep.pdf
    • http://juwopukob.calhounmiddleschoolband.com/uploads/1/3/2/8/132814930/36f280309f3947a.pdf
    • http://files.thairicekc.com/uploads/1/3/1/4/131483009/nesavorawu.pdf
    • https://cdn.shopify.com/s/files/1/0437/9970/7810/files/jogunikorute.pdf
    • https://cdn.shopify.com/s/files/1/0431/8032/7076/files/28525740760.pdf
    • https://cdn.shopify.com/s/files/1/0440/7354/9974/files/wunedevumep.pdf
    • https://cdn.shopify.com/s/files/1/0446/1517/2259/files/monanivakifin.pdf
    • https://cdn.shopify.com/s/files/1/0432/8721/6293/files/livonefopokapobewu.pdf
    • https://cdn.shopify.com/s/files/1/0449/8276/3679/files/65283673917.pdf
    • https://cdn.shopify.com/s/files/1/0434/5636/4711/files/91165203886.pdf
    • https://cdn.shopify.com/s/files/1/0432/3111/7467/files/24484342046.pdf
    • https://cdn.shopify.com/s/files/1/0428/6310/0070/files/bizar.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_off00006f6c.bin
a219defb42977dda0855960917049bb524af551e223705aee5f6d8d2b9de0c0c
pdf-font-stream PDF embedded font (sfnt) at offset 0x6F6C 5336 bytes
font_01_sfnt_off0000817f.bin
560513a6169102725856383cf3a7d44060593acfac6fe7e8cfc349c3970290c1
pdf-font-stream PDF embedded font (sfnt) at offset 0x817F 10536 bytes