Malicious PDF — malware analysis report

Static analysis result for SHA-256 40799f157a5a68f1…

MALICIOUS

PDF

73.6 KB Created: 2021-01-13 04:21:44 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: c8973f70e6aba0d2187532f4476a5ba1 SHA-1: a5858913c6fae53f69e80421f1f59e57800021b5 SHA-256: 40799f157a5a68f16b61f62ef2f389bb41491b623b109f591466a38f5d74ca71
126 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 hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the sheer volume of outbound links suggests a high likelihood of redirecting users to malicious or compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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.
  • 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://traffnew.ru/aws?utm_term=bid+bond+performance+bond+definition PDF link annotation
    • https://cdn.sqhk.co/lewivapawo/gBqmZhg/tabalawanoretoridu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418777/normal_5f9ddedc67244.pdfIn PDF document text
    • https://karadirivesu.weebly.com/uploads/1/3/1/4/131407010/6329056.pdfIn PDF document text
    • https://vowobonu.weebly.com/uploads/1/3/4/8/134853209/1c8043e47686.pdfIn PDF document text
    • https://bufigolumixi.weebly.com/uploads/1/3/4/2/134234787/belutapiwirijigef.pdfIn PDF document text
    • https://betebawaxudu.weebly.com/uploads/1/3/5/3/135388356/pofawezidaro-kisemebux-kexuvodasipeke-nopedem.pdfIn PDF document text
    • https://cdn.sqhk.co/zokelofid/EX4ibuo/geluxuwivetenotekuwire.pdfIn PDF document text
    • https://litufefanim.weebly.com/uploads/1/3/4/9/134901191/jilatifavuwufokob.pdfIn PDF document text
    • https://supavutoni.weebly.com/uploads/1/3/4/7/134713891/nupexorifuti.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489609/normal_5fbd901e9cff4.pdfIn PDF document text
    • https://rigivopamakor.weebly.com/uploads/1/3/4/8/134869382/6675c8f.pdfIn PDF document text
    • https://site-1175916.mozfiles.com/files/1175916/boku_no_pico_de_gallo_meaning.pdfIn PDF document text
    • https://rubajamepufukav.weebly.com/uploads/1/3/4/4/134432722/8142542.pdfIn PDF document text
    • https://site-1172340.mozfiles.com/files/1172340/woodcarving_supplies_uk.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d563.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD563 5068 bytes
SHA-256: fc2ad799d642a156530abf0a56f21174215591784e41ac63fdbdff5682be6f13
font_01_sfnt_off0000e675.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE675 10716 bytes
SHA-256: b0fe6d1b9e7f3e1c366938232802b6da26088134148dd55693d896efdbd11b5f
font_02_sfnt_off00010b1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1F 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176