Malicious PDF — malware analysis report

Static analysis result for SHA-256 0ec1d69776d1c564…

MALICIOUS

PDF

38.7 KB Created: 2020-09-03 15:55:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 6be7c21fe85b7e59a79a8b7aceb0b993 SHA-1: b108ff12762cef4392184aa5dd399191338ac938 SHA-256: 0ec1d69776d1c564d3e32e889b20d73b9edbe3a1a649b7b797ecaf88167af265
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a heuristic firing for linking to known malicious redirector infrastructure, specifically `https://ttraff.ru/wix?keyword=logarithm+word+problems+with+answers`. It also exhibits characteristics of a PDF link farm, with numerous embedded URLs pointing to external documents. The ML classifier strongly indicates maliciousness. The document body, though heavily obfuscated, contains the same malicious URL and several benign-looking URLs, suggesting an attempt to disguise the malicious intent.

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/wix?keyword=logarithm+word+problems+with+answers
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/8b9728_bec8fc789b2c49e2ad016ffef16049d0.pdf
    • https://static.usrfiles.com/ugd/1cc777_9dc23c4d62ad4a63b8d43ad46cef6a52.pdf
    • https://static.usrfiles.com/ugd/fb83f1_3acc6d6eb80f4a4fb63bf440310a2d3b.pdf
    • https://static.usrfiles.com/ugd/6f7357_88e5096c4ea04dfabc404cbf499b84b6.pdf
    • https://cdn.shopify.com/s/files/1/0437/6661/2119/files/commercial_real_estate_excel_templates.pdf
    • https://cdn.shopify.com/s/files/1/0431/5345/7320/files/ropabuzafofinavakomubirup.pdf
    • https://cdn.shopify.com/s/files/1/0437/4691/8551/files/application_letter_sample_for_internship.pdf
    • https://cdn.shopify.com/s/files/1/0430/1121/1425/files/lavabuporuxe.pdf
    • https://cdn.shopify.com/s/files/1/0428/0179/1132/files/texowej.pdf
    • https://cdn.shopify.com/s/files/1/0435/5080/2081/files/87180349710.pdf
    • https://cdn.shopify.com/s/files/1/0431/9268/0611/files/tanasurepodupagoxutoji.pdf
    • https://static.usrfiles.com/ugd/843280_69d50eedb18c406c8f881c7ae74983d2.pdf
    • https://static.usrfiles.com/ugd/b8c837_6ddf5f4dfa9344e29153c837d65911be.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000057a0.bin
e0a49ab22445ec0b87a52de46bae5e3a49d8f0027c5a1d25c1faad989ef0208f
pdf-font-stream PDF embedded font (sfnt) at offset 0x57A0 5544 bytes
font_01_sfnt_off00006a60.bin
59c1da89003e6879c996bf4c966583bc9069d9c542f4cf6449b7ca9e01de75f2
pdf-font-stream PDF embedded font (sfnt) at offset 0x6A60 10468 bytes