Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d66fda28b7e551b…

MALICIOUS

PDF

40.4 KB Created: 2020-06-12 05:26:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: acc3c96f274a3dbac0cef769b0d17de1 SHA-1: 496a057786fc6a47b600d254ee5a08a7243f9f47 SHA-256: 5d66fda28b7e551bd9147c38a593d581179a1cd54cfbc588febb66ee4e9dba75
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF document contains a large number of external links, many of which point to other PDF files hosted on various domains. This behavior is indicative of a link farm or SEO manipulation tactic, but given the malicious verdict, it is more likely used to distribute further malicious content or to obscure the true malicious destination. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

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://webmail.flyingleapimprov.net/uploads/1/3/1/4/131453521/131453521.html#forensic+chemistry+and+toxicology+pdf
    • http://oncallathletics.com/uploads/1/3/0/5/130590163/dimozojujojav.pdf
    • http://yourlovedoneshome.com/uploads/1/3/0/5/130539691/9473275605a9.pdf
    • http://fourcornerstribalbusinesscorporation.com/uploads/1/3/1/4/131411987/jipij_mixege_mumukug.pdf
    • http://realviewelectronics.com/uploads/1/3/0/6/130620565/fb136bf.pdf
    • http://mx.wendellmills.com/uploads/1/3/0/7/130776821/muzimov_sitigu_vuvigi_kukinozibebo.pdf
    • http://czid7.bpmtc.com/uploads/1/3/0/3/130379482/88b3962.pdf
    • http://mail.crushthemarket.com/uploads/1/3/0/2/130289189/933c2575bdacd7f.pdf
    • http://roeadvisers.com/uploads/1/3/1/3/131382680/7451213.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://tefizewu.files.wordpress.com/2020/06/15416579849.pdf
    • https://dekupuwapo627084595.files.wordpress.com/2020/06/finasadadumufuwubowaxex.pdf
    • https://banisozix.files.wordpress.com/2020/06/52420501192.pdf
    • https://depezexigit.files.wordpress.com/2020/06/58913832796.pdf
    • https://juzuzinon.files.wordpress.com/2020/06/korilijiku.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000070f7.bin
0b15532358e7116e6b3ef994d415f982bfae0a85e8d423d2b67764b996be8840
pdf-font-stream PDF embedded font (sfnt) at offset 0x70F7 10892 bytes