Malicious PDF — malware analysis report

Static analysis result for SHA-256 97403bd91c4ff548…

MALICIOUS

PDF

41.5 KB Created: 2020-08-15 14:42:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0e85cc2062bcdf374efdd0e34321773b SHA-1: fc3891af6cd8993356e31ac6b5e54ee04ab0c433 SHA-256: 97403bd91c4ff5480fc4108ec08389a40701512d382c5f7fd371b5fb021f4139
152 Risk Score

Malware Insights

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

The PDF contains embedded links, with one specifically identified as a malicious redirector pointing to a URL related to an 'amended 941 irs form'. The document body, though heavily corrupted, contains text fragments that align with this lure. The presence of a large number of external PDF links, many hosted on Shopify, suggests a link farm designed to distribute malicious content or improve SEO for malicious sites. The ML classifier strongly flagged this PDF as malicious.

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/pify?keyword=amended+941+irs+form
    • http://files.hustlecary.com/uploads/1/3/0/7/130775741/mopexoxuwo.pdf
    • http://files.mugstips.com/uploads/1/3/1/4/131407796/1465114.pdf
    • https://cdn.shopify.com/s/files/1/0433/4626/4213/files/josometijifemujusuvawe.pdf
    • https://cdn.shopify.com/s/files/1/0428/7738/6911/files/puxirunodogurime.pdf
    • https://cdn.shopify.com/s/files/1/0430/6416/4506/files/furegu.pdf
    • https://cdn.shopify.com/s/files/1/0432/4179/9843/files/check_your_aviation_english_download.pdf
    • https://cdn.shopify.com/s/files/1/0431/5312/9640/files/minecraft_seeds_pe_city.pdf
    • https://cdn.shopify.com/s/files/1/0433/7215/0942/files/70266778682.pdf
    • https://cdn.shopify.com/s/files/1/0437/7939/1637/files/75921499064.pdf
    • https://cdn.shopify.com/s/files/1/0429/6690/9081/files/walden_henry_david_thoreau_download.pdf
    • https://cdn.shopify.com/s/files/1/0454/3532/2526/files/effects_of_cyberbullying_on_students.pdf
    • https://cdn.shopify.com/s/files/1/0435/8799/3763/files/55199663153.pdf
    • https://cdn.shopify.com/s/files/1/0432/4635/4594/files/modern_digital_electronics_book_download.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_off00006443.bin
9a973c06a99f6285b202bf90145c87a9ec1e1dac92cdeaabc8c321af868a8af4
pdf-font-stream PDF embedded font (sfnt) at offset 0x6443 5096 bytes
font_01_sfnt_off00007588.bin
4acd88c73dd2caf0253dbbdba6fbd846fb48061f7a0814ea12508db924f8cb11
pdf-font-stream PDF embedded font (sfnt) at offset 0x7588 10572 bytes