Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdb0b2390997c44a…

MALICIOUS

PDF

36.4 KB Created: 2020-06-09 00:01:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-07
MD5: c7b82c6902d7eb73c739c830e3a92c34 SHA-1: 1c4ca93755dca572cb7f82643a0d663f838eae03 SHA-256: cdb0b2390997c44a8cf0f18a32f38118b3570acd95fd8b711daed559277e9863
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The PDF file contains a large number of external links, a technique often used for SEO manipulation or to distribute malicious content. The ML classifier strongly indicated maliciousness. The document body itself is heavily obfuscated but contains references to the external URLs, reinforcing the link farm attack pattern. No scripts were extracted, limiting the analysis of direct payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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 http://parents.sprigeo.com/uploads/1/3/1/3/131379824/131379824.html#jurnal+ekologi+hewan+pdf PDF link annotation
    • http://freefoodforthehomelessandthehungry.org/uploads/1/3/1/6/131636744/posiragidavagoso.pdfIn PDF document text
    • http://sijmit.com/uploads/1/3/1/1/131164573/555099.pdfIn PDF document text
    • http://m.janicedunhamskitchen.com/uploads/1/3/0/5/130550794/sarawanirusisas.pdfIn PDF document text
    • http://webmail.wariotofarminc.com/uploads/1/3/1/0/131069764/8750064.pdfIn PDF document text
    • http://luisaquezadayoga.com/uploads/1/3/0/8/130874426/mipewevobexen.pdfIn PDF document text
    • http://spsmgmtproposal.com/uploads/1/3/1/3/131383594/jonazaju.pdfIn PDF document text
    • http://blog.fundacionjuguemos.cl/uploads/1/3/0/5/130588529/f63b82.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://pagapulikuv.files.wordpress.com/2020/06/sutisumotukefukuxod.pdfIn PDF document text
    • https://vawixezaju.files.wordpress.com/2020/06/xidexapo.pdfIn PDF document text
    • https://bisapabak.files.wordpress.com/2020/06/vefesemewagetovonoboveb.pdfIn PDF document text
    • https://gepuwovu.files.wordpress.com/2020/06/fagofiw.pdfIn PDF document text
    • https://jemiropa.files.wordpress.com/2020/06/1095089960.pdfIn PDF document text
    • https://dozobozugut.files.wordpress.com/2020/06/gepaxobiresopamujabemexu.pdfIn PDF document text
    • https://gizedaresudi.files.wordpress.com/2020/06/boradoro.pdfIn PDF document text
    • https://memibenamefu.files.wordpress.com/2020/06/xivuwifusuzupapavojus.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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000062ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x62EA 10276 bytes
SHA-256: 2ace0f4e0b2fd0a67c26a44130d7b28feda619904270b808fe7b62fa3ea3c84d