Malicious PDF — malware analysis report

Static analysis result for SHA-256 61bbde9c5dcddc05…

MALICIOUS

PDF

54.9 KB Created: 2020-06-09 07:24:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8d190b52844316fc920931767123bbd3 SHA-1: e27c1c5bb66ad5c560976ed5567f944d15c5f4c4 SHA-256: 61bbde9c5dcddc055280aad4ec6632b9e526ab6574d9893263d6e9da96008af0
96 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a heuristic identifying it as a 'PDF_SEO_LINK_FARM' containing 24 links. The document body, though heavily obfuscated, contains a URL that matches one of the extracted links. The ML classifier strongly flagged this PDF as malicious, indicating a high likelihood of malicious intent behind the link farm. No scripts were extracted, but the structure suggests the PDF is designed to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • 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.
  • 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://narpestakpak.com/uploads/1/3/0/6/130639797/130639797.html#pes+2013+uefa+avrupa+ligi+yamas%25C4%25B1+2017
    • http://pamelasperryrealestate.com/uploads/1/3/0/5/130539944/vonobetovivep_fazabakolotab_pisanavugafika.pdf
    • http://bluetickfamous.com/uploads/1/3/1/3/131398529/pemufu_jadapuji_vuwofigabat_dozeforuf.pdf
    • http://ghawkinspect.com/uploads/1/3/1/0/131070895/8185364.pdf
    • http://74-123-77-178.mgwnet.com/uploads/1/3/0/4/130488833/naxobiwilibava-zorudi-witokoxeravimu-zufufuv.pdf
    • http://www.opentle.org
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://vekikilixowa.files.wordpress.com/2020/06/werikivadi.pdf
    • https://goduduwatike.files.wordpress.com/2020/06/motoxuleboforivimetejakab.pdf
    • https://depivufegel.files.wordpress.com/2020/06/42450178178.pdf
    • https://vizumabatum378344478.files.wordpress.com/2020/06/3671287814.pdf
    • https://nonuwivab179611077.files.wordpress.com/2020/06/85164372206.pdf
    • https://filemukaxene293587401.files.wordpress.com/2020/06/77479892898.pdf
    • https://zezumova.files.wordpress.com/2020/06/26532095990.pdf
    • https://nekidow.files.wordpress.com/2020/06/vikaxorafamufoxugoboma.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://www.gnu.org/licenses/gpl.html
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0000654c.bin
a79cd30b9d544d1667ad655be77dace3dcbdb25b864f82d7891baddaf971ffe0
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x654C 13004 bytes
font_01_sfnt_off00008a02.bin
ca3fd3bd2d5f2fc36fe1f94fa0e93148dc50b793add98bf01c7d51ddf5b9f892
pdf-font-stream PDF embedded font (sfnt) at offset 0x8A02 13416 bytes
font_02_sfnt_off0000b339.bin
ee50fc6c5f541a70eab4b37c1d42620a9fbf19a1a94f4f91281cde19e13a6de3
pdf-font-stream PDF embedded font (sfnt) at offset 0xB339 17972 bytes