Malicious PDF — malware analysis report

Static analysis result for SHA-256 551935f631a5eef4…

MALICIOUS

PDF

45.1 KB Created: 2020-08-14 12:56:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0f075f01ff70a005eae2174e34f7caed SHA-1: ae264be6cd7420e96561fb3ee8469e81aa98e4d1 SHA-256: 551935f631a5eef4778dd014952f3c24db40c632937c3b7b2b5f60440fc807aa
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a significant number of embedded links. One of these links points to a known malicious redirector, and many others form a link farm pointing to external PDF files. The document body contains garbled text and metadata indicating it was generated by wkhtmltopdf, suggesting it's not a legitimate document but rather a lure.

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=impressionistic+approach+guide+questions
    • http://ribiguf.annsangelsawf.org/uploads/1/3/1/0/131070598/2106681.pdf
    • http://files.314actionucla.com/uploads/1/3/1/3/131380847/2672732.pdf
    • http://files.kathrynbartlett.com/uploads/1/3/1/4/131483662/80740eb.pdf
    • https://cdn.shopify.com/s/files/1/0430/7563/3306/files/airport_vocabulary_english_exercises.pdf
    • https://cdn.shopify.com/s/files/1/0440/3236/0613/files/9532013873.pdf
    • https://cdn.shopify.com/s/files/1/0434/7949/8917/files/81056562602.pdf
    • https://cdn.shopify.com/s/files/1/0427/8029/5334/files/8539282913.pdf
    • https://cdn.shopify.com/s/files/1/0431/2694/7989/files/fosegulix.pdf
    • https://cdn.shopify.com/s/files/1/0430/6488/5397/files/accounting_theory_and_practice_textbook.pdf
    • https://cdn.shopify.com/s/files/1/0434/1560/1319/files/52825760051.pdf
    • https://cdn.shopify.com/s/files/1/0437/0428/7383/files/95989822725.pdf
    • https://cdn.shopify.com/s/files/1/0436/6086/9785/files/spanish_to_english_translation_document.pdf
    • https://cdn.shopify.com/s/files/1/0432/1837/0728/files/pesurolujatevewizero.pdf
    • https://cdn.shopify.com/s/files/1/0433/3692/5342/files/10336284947.pdf
    • https://cdn.shopify.com/s/files/1/0433/9941/3925/files/6821900552.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_off00007116.bin
a7e5096a1d927c8b34d4faea8090df7d19d4075647370a5427d05a8088291609
pdf-font-stream PDF embedded font (sfnt) at offset 0x7116 5520 bytes
font_01_sfnt_off0000839a.bin
f050b07fa6fdcec263af7f3bf49a616c39214bf4e4b11c219733c77056d4ad12
pdf-font-stream PDF embedded font (sfnt) at offset 0x839A 10532 bytes