Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa27c6f70cf0ab40…

MALICIOUS

PDF

40.8 KB Created: 2020-08-15 02:31:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 30acba297558eb283364a595558264fb SHA-1: ad92ddebc458d5c470d61efa7b7fe7120aba74e9 SHA-256: fa27c6f70cf0ab40ad8ded50b5f646c3e385b432fe4a37a5c9f540404e1e0470
152 Risk Score

Malware Insights

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

The PDF contains a link farm designed to redirect users to malicious infrastructure, specifically identified by the heuristic PDF_MALICIOUS_REDIRECTOR_LINK. The document body, though partially corrupted, indicates a lure related to 'free worksheets for preschool and kindergarten'. The primary malicious IOC is the redirector URL, which is likely the first step in a phishing or malware delivery chain.

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/wb?keyword=free%20worksheets%20for%20preschool%20and%20kindergarten
    • http://files.qualitycollectibletreasures.com/uploads/1/3/1/4/131406649/2084638e99d06.pdf
    • http://files.timbrownemf.com/uploads/1/3/1/4/131437093/pemakusemi.pdf
    • https://cdn.shopify.com/s/files/1/0438/3549/0461/files/88128930368.pdf
    • https://cdn.shopify.com/s/files/1/0433/1202/1657/files/xuzatomekojagadizis.pdf
    • https://cdn.shopify.com/s/files/1/0439/3422/0456/files/20469717732.pdf
    • https://cdn.shopify.com/s/files/1/0431/6548/3168/files/lixisexifin.pdf
    • https://cdn.shopify.com/s/files/1/0431/9641/6157/files/don_t_funk_with_my_heart_lyrics.pdf
    • https://cdn.shopify.com/s/files/1/0436/8865/7049/files/rutefudojupiwuduj.pdf
    • https://cdn.shopify.com/s/files/1/0431/5840/5274/files/71664686684.pdf
    • https://cdn.shopify.com/s/files/1/0437/1188/9562/files/66618074164.pdf
    • https://cdn.shopify.com/s/files/1/0434/9178/6918/files/punikubitilapuja.pdf
    • https://cdn.shopify.com/s/files/1/0431/4795/2294/files/bumibovajerip.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_off0000612a.bin
63366877420bf1fce02eeabd49e85f840f40e9a5dd566aefcf9ac1022b4f8543
pdf-font-stream PDF embedded font (sfnt) at offset 0x612A 5528 bytes
font_01_sfnt_off0000740a.bin
152fdbbefe97e8702f879b784b06769bf1ecb02a834eb991cca16c391fcd57c7
pdf-font-stream PDF embedded font (sfnt) at offset 0x740A 10044 bytes