Malicious PDF — malware analysis report

Static analysis result for SHA-256 25eeab2852ac04d4…

MALICIOUS

PDF

37.0 KB Created: 2020-08-25 04:32:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cc6e304e4070d8f2fd2df20b9dd06ed1 SHA-1: 8361deb4f104bdc733c5f6f3ff077794a7dfee80 SHA-256: 25eeab2852ac04d4912c36c49863cb55317145a8d17d64318923248c6634cdca
152 Risk Score

Malware Insights

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

The PDF contains a link farm, with one URL pointing to a known malicious redirector. The document body, though heavily obfuscated, contains the text 'Blake chart worksheet' and the malicious URL, suggesting a lure to trick the user into clicking the link. The ML classifier also strongly indicated maliciousness.

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=blake+chart+worksheet
    • http://files.maetcheconstruction.com/uploads/1/3/1/8/131856389/871ae46e87.pdf
    • http://bovojoru.brian-nacov.com/uploads/1/3/0/8/130874180/cab17d.pdf
    • http://zijog.firstathens.org/uploads/1/3/1/6/131606629/8911a3be1e27db.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/guwesimutetalajizobanubel.pdf
    • https://cdn.shopify.com/s/files/1/0428/9187/0375/files/boost_c_latest.pdf
    • https://cdn.shopify.com/s/files/1/0436/7525/4937/files/piposi.pdf
    • https://cdn.shopify.com/s/files/1/0430/5803/6889/files/carteret_county_news_times_crime_report.pdf
    • https://cdn.shopify.com/s/files/1/0447/3035/1770/files/6th_grade_probability_worksheets.pdf
    • https://cdn.shopify.com/s/files/1/0430/6635/9962/files/54959176463.pdf
    • https://cdn.shopify.com/s/files/1/0429/6821/9799/files/pizamebulofajajaxus.pdf
    • https://cdn.shopify.com/s/files/1/0431/9048/5150/files/lipid_lowering_drugs_pharmacology.pdf
    • https://cdn.shopify.com/s/files/1/0431/7039/8362/files/ashrae_1997_hvac_fundamentals_handbook.pdf
    • https://cdn.shopify.com/s/files/1/0431/9199/2480/files/kifeg.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_off000054d1.bin
990f76fb78389aba7d479b279175d0a88f5657dbd161e67a1918b7d996a28346
pdf-font-stream PDF embedded font (sfnt) at offset 0x54D1 5092 bytes
font_01_sfnt_off0000662c.bin
25813662643638c9abeb37d2557eb1973ccbf48397472b75eaadd98d90ed995e
pdf-font-stream PDF embedded font (sfnt) at offset 0x662C 9832 bytes