Malicious PDF — malware analysis report

Static analysis result for SHA-256 7cd90a808e6f20f2…

MALICIOUS

PDF

45.2 KB Created: 2020-09-01 01:45:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ef97c8af15276cf4254abe823df0adaa SHA-1: 0cfacb856d9abdb29021557daab0c16cffcbc4dc SHA-256: 7cd90a808e6f20f2f043f67089e94eb9059c8366f67b3d80e8469ce4cc6501ee
152 Risk Score

Malware Insights

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

The PDF contains a mass of external links, many pointing to a link farm infrastructure. One prominent link, https://ttraff.cc/wix?keyword=codility+interview+questions+and+answers, is identified as a malicious redirector. The document body, though partially corrupted, suggests a lure related to 'Codility interview questions and answers', likely intended to trick users into clicking the malicious links.

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/wix?keyword=codility+interview+questions+and+answers
    • https://static.usrfiles.com/ugd/4b874d_fc43c196c1354e15ad4546775f7c4243.pdf
    • https://static.usrfiles.com/ugd/97368a_4317854b33554b8582fe2e6026192e93.pdf
    • https://static.usrfiles.com/ugd/0cd3a8_c68d1dd3e3e64a60ac196c2b87d43ee2.pdf
    • https://static.usrfiles.com/ugd/b8c837_042db4c71278417f95a5e63d6f565598.pdf
    • https://static.usrfiles.com/ugd/b85eb0_ceeb385ecebe4a6e876eea286b7bf659.pdf
    • https://static.usrfiles.com/ugd/ec0c41_9662644a775440fdbd222c0bb3ff0a73.pdf
    • https://static.usrfiles.com/ugd/0e2875_6e8ef3142de3424c9bb3cedb01a1ab0d.pdf
    • https://static.usrfiles.com/ugd/a1fb72_b53d8b714ad6482dbe63e608f1250a19.pdf
    • https://static.usrfiles.com/ugd/b8c837_32bc560b756d44e78d1964fecf29cc72.pdf
    • https://static.usrfiles.com/ugd/e1d12c_fe337daa4e6145f6b4f8f30c4e68008d.pdf
    • https://static.usrfiles.com/ugd/b8c837_2c5b2d63d23244fd94b587fa27ec72a3.pdf
    • https://cdn.shopify.com/s/files/1/0430/5308/8921/files/the_first_book_of_adam_and_eve_download.pdf
    • https://cdn.shopify.com/s/files/1/0435/8494/6333/files/above_all_powers_lyrics_and_chords.pdf
    • https://cdn.shopify.com/s/files/1/0431/4837/8274/files/subject_verb_agreement_exercises_grade_6.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_off000073de.bin
b523d7ea60348df9a37c6fa94ab014bf004810c2267acc10b417beb918f09fb4
pdf-font-stream PDF embedded font (sfnt) at offset 0x73DE 5104 bytes
font_01_sfnt_off00008559.bin
ff75a75330b6848dfb4cb7a979f091b4431addb926af39a4b2a67b5ebb8225a4
pdf-font-stream PDF embedded font (sfnt) at offset 0x8559 10120 bytes