Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9f085b3820c7ec4…

MALICIOUS

PDF

78.4 KB Created: 2021-04-26 12:41:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: cf35ec943993f68ab1d0533ea24fd53c SHA-1: 37b341e9ef64b00202cb952f026ed408683780f2 SHA-256: c9f085b3820c7ec4f8369f888514941787dfd01d128b717424b57f2d522d8104
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/strik?utm_term=how+do+i+print+a+lease+agreement PDF link annotation
    • https://cdn.sqhk.co/godezixibufo/bhfDyhf/58631691459.pdfIn PDF document text
    • https://cdn.sqhk.co/bikakigiben/Fia2Mjd/zorabelerugodifo.pdfIn PDF document text
    • https://cdn.sqhk.co/gesokusa/DhejbDH/xedozawev.pdfIn PDF document text
    • https://cdn.sqhk.co/wenewojufaj/qrVijgd/47633542841.pdfIn PDF document text
    • https://cdn.sqhk.co/woselukafo/jKwtjd5/musilitazijal.pdfIn PDF document text
    • https://cdn.sqhk.co/fifotadog/iiPhgzq/spanglish_imdb_parents_guide.pdfIn PDF document text
    • https://cdn.sqhk.co/xegunorasu/gibkTWB/vibaxixipogezuvipe.pdfIn PDF document text
    • https://cdn.sqhk.co/lojulifuvuxu/jjjbgfi/bosidijetufewugak.pdfIn PDF document text
    • https://cdn.sqhk.co/mekoposa/0gdjcH3/6853627782.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/64201e46-3d11-4838-98cf-16a38ae1de4c/rijonelovidewivonolapuzur.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/910cf9e6-ad44-4e4c-8de4-a3682cd5cea7/88494618310.pdfIn PDF document text
    • https://f64a1a0a-debf-4843-a838-a34c0cae0f4a.filesusr.com/ugd/89602e_72ae39b17d3b4792a165f41948a95a03.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f896d1ee-e85c-4ca1-9b4d-d4136c747127/lekuwilerukuma.pdfIn PDF document text
    • https://8eccd3b7-fb20-4588-a5b5-4d8c58591879.filesusr.com/ugd/0e6328_8455e212dade44eaa0e933ae5c3f857f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/795ffc7a-b29c-4ef9-9fce-f88cd7886709/65772610690.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/20bbd885-e1e5-429a-8430-a4393e6753e4/jisibifudede.pdfIn PDF document text
    • https://6c71f620-b6e5-46cc-9e58-526c5f0a7a41.filesusr.com/ugd/1c90dc_85b7dbaa24cb4ee29dd0d5a3da2fbefb.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9bfa8847-b02a-4301-a6bb-c2e5825a6c8d/childrens_bible_stories_online_for_free.pdfIn PDF document text
    • https://s3.amazonaws.com/rakabexozu/75248156391.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b343d1c5-f747-4766-9fdd-ba03c6caa27c/momekaserewuboteruj.pdfIn PDF document text
    • https://s3.amazonaws.com/laginekux/677453315.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2ad674fb-f0b7-4f77-92f6-eb12dfc5532c/wakenodunanusitedegorafo.pdfIn PDF document text
    • https://fb79ad55-22b5-4823-9538-35c71bbbd514.filesusr.com/ugd/ea423f_11cb328cbadf419f9b24d5a3fdc9a5c3.pdf?index=trueIn PDF document text
    • https://ac25a69f-a984-4293-9c3d-8c9e0f062535.filesusr.com/ugd/cbf077_15bc089ff68e46a68fc27b6b8c6a3608.pdf?index=trueIn 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_off0000f698.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF698 5332 bytes
SHA-256: a0c59070256e46dc315d0f717bc668864527c2659b59cfbfa4c9b6944baee5ae
font_01_sfnt_off000108b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B1 10372 bytes
SHA-256: c9bb26500edc8f23d84dc90c827180fd17889879cc97da148ffd2b5a7323fb63