Malicious PDF — malware analysis report

Static analysis result for SHA-256 e19d55a46b640673…

MALICIOUS

PDF

35.3 KB Created: 2020-08-19 11:15:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d8e09f692e76c1ddd5ac4c44e1699a02 SHA-1: 91f35e24aabb064de03e6d00adc5c614c8cc86b3 SHA-256: e19d55a46b64067304d3dae9cc718577e96e4a2799a7795f11fd63eac000f653
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to Shopify domains, but one critical link directs to a known malicious redirector at ttraff.com. The document body, though heavily obfuscated, contains text suggesting it is an 'American english file 3 workbook answer key', which serves as a lure. The ML classifier strongly flagged this PDF as malicious, and the presence of a malicious redirector indicates an attempt to lead the user to a harmful site.

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.com/pify?keyword=american+english+file+3+workbook+answer+key
    • http://doxisapo.abamericanhistory.com/uploads/1/3/1/3/131378960/rekavemu_wilox.pdf
    • http://files.jimcottrill.com/uploads/1/3/1/6/131637291/3790801.pdf
    • http://files.marchemcmillan.ca/uploads/1/3/2/8/132814969/4829934.pdf
    • https://cdn.shopify.com/s/files/1/0429/6612/2662/files/16423054851.pdf
    • https://cdn.shopify.com/s/files/1/0437/0795/7400/files/eating_disorder_guidelines_queensland.pdf
    • https://cdn.shopify.com/s/files/1/0433/6638/3768/files/gaxofekogopifavakufi.pdf
    • https://cdn.shopify.com/s/files/1/0433/6150/1336/files/peer_gynt_henrik_ibsen.pdf
    • https://cdn.shopify.com/s/files/1/0433/0805/6740/files/gonusutiwasunob.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/31443612403.pdf
    • https://cdn.shopify.com/s/files/1/0434/4931/9577/files/beginner_english_words.pdf
    • https://cdn.shopify.com/s/files/1/0437/9541/5189/files/pid_controller_algorithm_source_code.pdf
    • https://cdn.shopify.com/s/files/1/0437/7500/0730/files/all_branches_of_engineering.pdf
    • https://cdn.shopify.com/s/files/1/0430/0659/1127/files/certificate_border.pdf
    • https://cdn.shopify.com/s/files/1/0434/5564/3813/files/49770890728.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_off00004779.bin
ccf2808514e4e5429c69f0d5210031dbdd9c73f6479aa4e2f4bc18c1444fd7f8
pdf-font-stream PDF embedded font (sfnt) at offset 0x4779 5848 bytes
font_01_sfnt_off00005b46.bin
68a7cc8f1caf8a27f3f26739208fc18135ae8bb3fd153e366b5ba5fb05ddef50
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B46 10480 bytes