Malicious PDF — malware analysis report

Static analysis result for SHA-256 85752f304dfeadad…

MALICIOUS

PDF

42.4 KB Created: 2020-07-31 21:36:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e20b8667c14dc984815fbabdfef6576d SHA-1: 80bea8b3e2d6b00e215c0f776fd14680c23ad7f7 SHA-256: 85752f304dfeadad2f822479200f3e03f58894737fc599c2f7fb5021eedd8564
154 Risk Score

Malware Insights

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

The PDF was flagged as malicious by a critical heuristic due to its inclusion of a link to known malicious redirector infrastructure. Additionally, it contains a large number of external links, identified as a PDF link farm, with the primary purpose of driving traffic to potentially harmful sites. The ML classifier strongly supported the malicious verdict. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the link structure and heuristic firings.

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=curl+post+parameters
    • http://files.heathermccallphotography.com/uploads/1/3/1/3/131381640/ced1f87c.pdf
    • http://files.kandersonmusic.net/uploads/1/3/1/1/131163949/bisivutumakobijuferi.pdf
    • http://files.hughespropertymaintenance.co.uk/uploads/1/3/1/4/131407635/712664.pdf
    • http://files.19thstreetchurchofchrist.com/uploads/1/3/1/1/131164382/07f26.pdf
    • http://files.orwellbiblechurch.org/uploads/1/3/1/8/131871488/7377478.pdf
    • https://cdn.shopify.com/s/files/1/0433/1565/8920/files/25941390215.pdf
    • https://cdn.shopify.com/s/files/1/0434/7504/2457/files/66102016304.pdf
    • https://cdn.shopify.com/s/files/1/0437/0015/8629/files/89824246241.pdf
    • https://cdn.shopify.com/s/files/1/0431/6073/1808/files/finisod.pdf
    • https://cdn.shopify.com/s/files/1/0431/6463/1195/files/gamesibomuvotepogerefaxo.pdf
    • https://cdn.shopify.com/s/files/1/0433/5632/3995/files/dojobotelosegeg.pdf
    • https://cdn.shopify.com/s/files/1/0430/4997/5961/files/98793836257.pdf
    • https://cdn.shopify.com/s/files/1/0432/7194/6398/files/88674633554.pdf
    • https://cdn.shopify.com/s/files/1/0428/0179/1132/files/94150578652.pdf
    • https://cdn.shopify.com/s/files/1/0432/1991/0811/files/96845955676.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_off000066dc.bin
d36f98e4ac11f914c997f1962da89e371623b82ccd59a907094d358462663a3a
pdf-font-stream PDF embedded font (sfnt) at offset 0x66DC 4868 bytes
font_01_sfnt_off0000774a.bin
fa28ee7c951c43a82351b4731b70d4ac5089b7eaff2900acd3070930422ddd7e
pdf-font-stream PDF embedded font (sfnt) at offset 0x774A 10976 bytes