Malicious PDF — malware analysis report

Static analysis result for SHA-256 735fbeb9ef14d90d…

MALICIOUS

PDF

44.8 KB Created: 2020-05-23 00:08:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 68e83150d7c5bf8e03731abe8632d932 SHA-1: ac85f2e958eb3c0bc876ed53b7a127b6379809af SHA-256: 735fbeb9ef14d90d1aa6f0046467ce69370e6d30e828eb6bc09c52d995ca41cb
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links to other PDF files hosted on various domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this sample as malicious, and the presence of numerous algorithmically generated URLs suggests an automated content generation process for SEO spam or to host malicious payloads. No scripts were extracted, but the sheer volume of outbound links points to a malicious intent to redirect the user to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://hiddeneclipse.com/uploads/1/3/0/6/130620906/130620906.html#liftmaster+security+plus+2.0+owner%2527s+manual
    • http://danielsperoni.com/uploads/1/3/0/7/130775136/surowonukewo.pdf
    • http://californiaapprovedpipespecialist.com/uploads/1/3/0/5/130588376/1ec013c96e.pdf
    • http://bgatpmp.com/uploads/1/3/0/8/130874501/jifewujamoj-zapobevorexew.pdf
    • http://bringingthishomewithheidi.com/uploads/1/3/1/6/131637870/064665122.pdf
    • http://bdbbetting.com/uploads/1/3/0/4/130489066/30a5b3eb63dbe6f.pdf
    • http://flyingvivaldi.com/uploads/1/3/0/7/130776123/0f6dc7f2ba9c.pdf
    • http://aloetteofnwva.com/uploads/1/3/0/4/130483319/pofimajoko.pdf
    • http://yarnwallows.com/uploads/1/3/1/3/131398591/pobujomikipeg_tateximinoloba.pdf
    • http://beautifulskinatlanta.com/uploads/1/3/1/3/131380623/4294904.pdf
    • http://webmail.davisbands.org/uploads/1/3/0/6/130620849/lotokugazin-todivitumezek.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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/
    • http://scripts.sil.org/OFL

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00008143.bin
49824a72e3eb9c514dc126d60bae109bf54efb533990394fc3ec834c2a64e3c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x8143 11328 bytes