Malicious PDF — malware analysis report

Static analysis result for SHA-256 523449392155aec9…

MALICIOUS

PDF

50.0 KB Created: 2020-08-10 18:58:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e38b16266299d88065b559ea88ef28f3 SHA-1: d9ead59d48fa9a52462dfecda592e3ab9e1190b5 SHA-256: 523449392155aec9169e76488999deb1fe4bc368fa59e04c50f451a18e3a8d1c
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with one identified as a malicious redirector. The heuristic PDF_SEO_LINK_FARM indicates a mass external PDF link farm, suggesting a SEO poisoning or link farm attack. The ML classifier also strongly flagged this PDF as malicious. The primary malicious IOC is the redirector URL.

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=esp%25C3%25A9cies+de+atos+administrativos+pdf
    • http://files.kelmaraircraftsales.com/uploads/1/3/2/7/132740488/4819381.pdf
    • http://rarixoro.thetaoofrudy.net/uploads/1/3/1/8/131856772/sazux.pdf
    • http://files.brandtheinterpreter.com/uploads/1/3/1/4/131407135/147adc80a80b616.pdf
    • https://cdn.shopify.com/s/files/1/0431/6450/0122/files/sotizufavigafavilibemelow.pdf
    • https://cdn.shopify.com/s/files/1/0434/7353/5138/files/80962344004.pdf
    • https://cdn.shopify.com/s/files/1/0432/6211/6008/files/fetapatejitulomuf.pdf
    • https://cdn.shopify.com/s/files/1/0427/4287/4278/files/wimow.pdf
    • https://cdn.shopify.com/s/files/1/0440/6686/5302/files/genetics_neet_questions_download.pdf
    • https://cdn.shopify.com/s/files/1/0431/6728/5408/files/ziwotexesotagolixasutenu.pdf
    • https://cdn.shopify.com/s/files/1/0427/6020/8540/files/tiridodogow.pdf
    • https://cdn.shopify.com/s/files/1/0429/6900/6236/files/98637268971.pdf
    • https://cdn.shopify.com/s/files/1/0432/9770/2046/files/63925585677.pdf
    • https://cdn.shopify.com/s/files/1/0435/2281/8200/files/jukasem.pdf
    • https://cdn.shopify.com/s/files/1/0437/1080/8217/files/22896547515.pdf
    • https://cdn.shopify.com/s/files/1/0431/2812/7645/files/zifijolutolelarinamovive.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_off0000814f.bin
17e4c10f9c8708d27eb81de358400cdd57fd26f2034c0f9612bd640958b970da
pdf-font-stream PDF embedded font (sfnt) at offset 0x814F 5428 bytes
font_01_sfnt_off0000936f.bin
8a51e2a91373e4b38489305a855ac448168fe559c380583394eddf9aece281a4
pdf-font-stream PDF embedded font (sfnt) at offset 0x936F 12528 bytes