Malicious PDF — malware analysis report

Static analysis result for SHA-256 f583f5b574b8d3b1…

MALICIOUS

PDF

42.4 KB Created: 2020-08-03 16:42:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ee50e32a9f51ac9ab8066428268473bc SHA-1: f9246e6233b29cccc3e1169498538d0046b0c61b SHA-256: f583f5b574b8d3b111294af66fe553c78d380aeab00e9eaf7ec83e28fb7da929
152 Risk Score

Malware Insights

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

The PDF file contains a significant number of embedded URLs, many of which are part of a link farm strategy. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK indicates that at least one URL points to known malicious redirector infrastructure. The ML classifier also strongly flagged this PDF as malicious. The document body contains text related to '6th grade math problems and answers pdf' and the wkhtmltopdf generator, suggesting a lure to disguise the malicious link farm.

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=6th+grade+math+problems+and+answers+pdf
    • http://files.foundationsoffuninfirst.com/uploads/1/3/0/8/130814118/93036.pdf
    • http://files.mufflerdelete.com/uploads/1/3/1/6/131637701/retizef.pdf
    • http://files.todayhousing.com/uploads/1/3/0/9/130969243/vanamogukalazak.pdf
    • https://cdn.shopify.com/s/files/1/0430/4338/9597/files/dilokotibetanimegeni.pdf
    • https://cdn.shopify.com/s/files/1/0435/8170/2303/files/atsg_4l60e_rebuild_manual.pdf
    • https://cdn.shopify.com/s/files/1/0430/4168/5665/files/jurobeferilemedubejer.pdf
    • https://cdn.shopify.com/s/files/1/0432/1021/1491/files/is_limewire_still_available.pdf
    • https://cdn.shopify.com/s/files/1/0432/5824/9376/files/zamulobizewinisimo.pdf
    • https://cdn.shopify.com/s/files/1/0429/3863/0300/files/wudake.pdf
    • https://cdn.shopify.com/s/files/1/0429/6579/4969/files/13985509173.pdf
    • https://cdn.shopify.com/s/files/1/0430/6275/5490/files/63473612277.pdf
    • https://cdn.shopify.com/s/files/1/0433/6504/0286/files/4085955706.pdf
    • https://cdn.shopify.com/s/files/1/0434/5679/0678/files/gimexalav.pdf
    • https://cdn.shopify.com/s/files/1/0430/2422/0321/files/zokavirikiwilek.pdf
    • https://cdn.shopify.com/s/files/1/0428/1715/9335/files/25752642007.pdf
    • https://cdn.shopify.com/s/files/1/0433/9941/3925/files/17233976072.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_off0000648f.bin
ca63f8339eecd4c1e588ba2a3f0d98cb200466dbc2cd596e701a553e91452787
pdf-font-stream PDF embedded font (sfnt) at offset 0x648F 5748 bytes
font_01_sfnt_off000077fe.bin
395343abeee352b88e60c8419a7716f482582120b48c0e1b74efa9ed9a292309
pdf-font-stream PDF embedded font (sfnt) at offset 0x77FE 10600 bytes