Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fc27335d2257975…

MALICIOUS

PDF

40.4 KB Created: 2020-07-26 18:58:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: fc71cf79e1d2cb5041dec7b18aa99f4c SHA-1: e1ee355a7acfa8ffe1587a13cf409f30ea82b588 SHA-256: 4fc27335d2257975c9ae6e4bd5f4d3f484cb6639431c7e0829b80fa69573ce0c
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.001 User Execution: Malicious Link T1059.001 PowerShell

The PDF contains a large number of embedded links, with a critical heuristic firing for a PDF link farm. One of the primary links points to a known malicious redirector. The document body, though heavily obfuscated, contains text related to 'exponential growth graph worksheet', suggesting a lure. The presence of numerous Shopify URLs, some confirmed benign and others unknown, indicates an attempt to blend malicious links with legitimate-looking content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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/wb?keyword=exponential%20growth%20graph%20worksheet In PDF document text
    • http://files.brittanysloan.com/uploads/1/3/0/7/130740130/bimug.pdfIn PDF document text
    • http://files.evolvepaintcolorado.com/uploads/1/3/2/3/132303083/fe85836a8e9b.pdfIn PDF document text
    • http://files.dunphyshandguntraining.com/uploads/1/3/2/6/132681566/d354c601d.pdfIn PDF document text
    • http://files.ambleon.net/uploads/1/3/1/0/131070125/zulalusimutolosu.pdfIn PDF document text
    • http://files.centre5pinbowl.ca/uploads/1/3/1/4/131407493/4234491.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/1534434062.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0440/6666/8694/files/36975950586.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/9279/5801/files/dedaburosotam.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0435/1829/6228/files/20398921863.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/8522/6393/files/wobiwokukesun.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0435/9333/4947/files/17424737697.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/9277/8912/files/bozomanajefepexopofuz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0127/3758/files/35318940017.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/3802/3592/files/56910086594.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0438/9247/4011/files/89644693138.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/9705/4631/files/kenezutusebitumunaw.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/9286/9281/files/45758141538.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6110 5052 bytes
SHA-256: 5386a5053aba980639a3048d8ab74e31d55466a37092eebedef1ad2070024e13
font_01_sfnt_off0000723c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x723C 9844 bytes
SHA-256: 346cb9bf1d1add72fda829b13a7db85406184967470aa47f55073b07daf7f3b7