Malicious PDF — malware analysis report

Static analysis result for SHA-256 13c75307d524b8d9…

MALICIOUS

PDF

78.7 KB Created: 2021-03-30 13:07:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 7e05adc70e35e5bf55fe99fc9751192e SHA-1: 8584260d0b9b102ba6654e35323d6f8f0ac99731 SHA-256: 13c75307d524b8d9d4aa1f7ff97d206e8b13e51e599653857d01703bce91fadf
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The sample is a PDF containing a large number of external links, identified as a link farm. The primary purpose appears to be directing users to various websites, as indicated by heuristics like PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM. While no scripts were explicitly extracted, the PDF structure and the presence of external URLs suggest it could be used for phishing or to download further malicious content, aligning with T1566.001 and potentially T1059.007 if JavaScript is embedded within the linked PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 https://ponafet.ru/award?keyword=difference+between+nationalism+and+patriotism+pdf PDF link annotation
    • http://unityfree.xyz/inheritance_series_book_43xmui.pdfIn PDF document text
    • https://cdn.sqhk.co/maweveju/jGrjegc/bali_travel_guide.pdfIn PDF document text
    • https://komutezux.weebly.com/uploads/1/3/1/3/131398036/de59c08.pdfIn PDF document text
    • http://50offstore.pro/life_and_death_stephenie_meyer6kco4.pdfIn PDF document text
    • https://cdn.sqhk.co/dusujukakal/fgck1ii/finixu.pdfIn PDF document text
    • https://vixufavem.weebly.com/uploads/1/3/2/6/132683014/muwukovoraramav-novuzuwes-jigij.pdfIn PDF document text
    • http://kengoru.space/11369722754q792b.pdfIn PDF document text
    • https://cdn.sqhk.co/fovipobex/RmAhe5B/digimon_rearise_apk.pdfIn PDF document text
    • https://novadoja.weebly.com/uploads/1/3/4/8/134873208/2480525.pdfIn PDF document text
    • https://cdn.sqhk.co/mivezifov/hixijhd/maze_runner_book_or_movie.pdfIn PDF document text
    • https://jonelezada.weebly.com/uploads/1/3/4/6/134603833/7168634.pdfIn PDF document text
    • https://cdn.sqhk.co/javomekoru/jvhfPNA/my_story_malayalam_movie_song_lyrics.pdfIn PDF document text
    • http://berkeciftci.net/22843760048nszqb.pdfIn PDF document text
    • https://cdn.sqhk.co/joxipadij/hd6zZjj/emirates_auction_abu_dhabi.pdfIn PDF document text
    • https://vuxabodunufa.weebly.com/uploads/1/3/1/4/131407539/vaveti-rawaduw-tijegepadivoxu-bevopov.pdfIn PDF document text
    • https://cdn.sqhk.co/tiviluluje/yageEij/best_satisfying_slime_video_ever.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://77bc4ea4-de20-41c0-a463-a5315db628d9.filesusr.com/ugd/2c69e3_7a97df33fdb148e48cb4a82174ee0d5c.pdf?index=trueIn PDF document text
    • http://wotexel.rf.gd/27179433325.pdfIn PDF document text
    • https://40c507a3-37b7-491f-afd3-f28ba3af1fb2.filesusr.com/ugd/7f5264_4b120e1d032a430dab9d98ae82d849be.pdf?index=trueIn PDF document text
    • http://beduxuluwuniva.rf.gd/popekalug.pdfIn PDF document text
    • https://2225f16e-b6a0-48e2-a067-d7e802b71dd4.filesusr.com/ugd/a7ada4_f61b67ee4f63480db4020e5d9c6338af.pdf?index=trueIn PDF document text
    • https://33edd578-4186-4695-89f3-f56a5a23fc53.filesusr.com/ugd/f17c08_e7f9676978654539952214bbb6618553.pdf?index=trueIn PDF document text
    • https://189c2d36-84ff-4b81-9465-96c33c1d3b91.filesusr.com/ugd/35ddae_4a97f87a17d244ae8529309eec5571ea.pdf?index=trueIn PDF document text
    • http://lofatis.epizy.com/dotomokirisoxalagowusa.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f367.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF367 5532 bytes
SHA-256: b8709666fc21446c396faf61654dd9e1be582a9b2b379073d1ff02d9864e63b6
font_01_sfnt_off00010636.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10636 11292 bytes
SHA-256: 5998772fea6c48b6260f416bb31e7bc8b61a6b3f24e09a87459e0e7bacc1f539