Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5f1f17de3924f43…

MALICIOUS

PDF

34.6 KB Created: 2020-08-19 01:17:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d1606dfefbfca2fbbbc5b24e3ab46660 SHA-1: d9ef60c23fc9f74f522b2dd3b4327d3040de61cc SHA-256: c5f1f17de3924f43c04612efed1cb88aab3da838e1df0c4ce86ed3a66d7d6bde
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic identifying a link to known malicious redirector infrastructure at 'https://ttraff.ru/pify?keyword=subject+pronouns+and_the_verb_ser_worksheet'. Another critical heuristic indicates a PDF link farm, with many links pointing to Shopify domains, likely to obscure the malicious intent. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is designed to distribute malicious content or phish users.

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=subject+pronouns+and+the+verb+ser+worksheet
    • http://jaradoba.richmondinfo.net/uploads/1/3/1/6/131606349/8224255.pdf
    • http://kotapeg.melgough.com/uploads/1/3/0/7/130776046/3e354348046.pdf
    • https://cdn.shopify.com/s/files/1/0429/1647/9132/files/movezuwagezo.pdf
    • https://cdn.shopify.com/s/files/1/0450/3538/9086/files/41931704603.pdf
    • https://cdn.shopify.com/s/files/1/0427/4189/1238/files/saxatorovubuvoniremesiwa.pdf
    • https://cdn.shopify.com/s/files/1/0430/8631/5684/files/palobiletewar.pdf
    • https://cdn.shopify.com/s/files/1/0432/5048/3368/files/5th_grade_math_curriculum.pdf
    • https://cdn.shopify.com/s/files/1/0432/5569/3470/files/mechanical_vibrations_5th_edition.pdf
    • https://cdn.shopify.com/s/files/1/0433/6464/7077/files/cysa_study_guide.pdf
    • https://cdn.shopify.com/s/files/1/0435/3359/8880/files/tewezexizapivepu.pdf
    • https://cdn.shopify.com/s/files/1/0432/0506/6913/files/votesorugamagig.pdf
    • https://cdn.shopify.com/s/files/1/0428/6965/3663/files/gigejonifolure.pdf
    • https://cdn.shopify.com/s/files/1/0431/0430/5303/files/amma_kavithai_in_tamil.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_off00004880.bin
156fe261cef56cb88efcfadd6e612a0a20ff39bde5a88b03cb2007aacd009722
pdf-font-stream PDF embedded font (sfnt) at offset 0x4880 5664 bytes
font_01_sfnt_off00005bc8.bin
396795e2803675ff3fec33f0757aa2b92f26bfb7075213e4744c583b08d4d5f4
pdf-font-stream PDF embedded font (sfnt) at offset 0x5BC8 9940 bytes