Malicious PDF — malware analysis report

Static analysis result for SHA-256 c854aea2e2756114…

MALICIOUS

PDF

82.7 KB Created: 2021-05-22 16:32:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: f06385597ce987da8c19db7633bda51e SHA-1: c4b9fea46bd6bf435412b8d2db5fa513bef4b4b0 SHA-256: c854aea2e2756114174e6504e332453216f4939f4884f22037d81ead02978ea5
254 Risk Score

Malware Insights

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

The PDF contains a high number of embedded links, many pointing to a redirector URL, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, contains metadata related to wkhtmltopdf, suggesting it was generated programmatically.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://yafferge.ru/strik?utm_term=diversifiable+risk+dan+non-diversifiable+risk In PDF document text
    • https://cdn-cms.f-static.net/uploads/4378149/normal_600b72bfb975f.pdfIn PDF document text
    • https://mudekireziwafa.weebly.com/uploads/1/3/4/7/134730614/pagiwosuxazonevebona.pdfIn PDF document text
    • https://sixifemawo.weebly.com/uploads/1/3/4/4/134470876/tuzomefipukivizosun.pdfIn PDF document text
    • https://vusexojepaxeva.weebly.com/uploads/1/3/4/0/134096357/ed8a1b4ca15e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4530171/normal_6003685c4b48d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403940/normal_604639e2170df.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369496/normal_604d64b46ca8b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450249/normal_60374df012ef6.pdfIn PDF document text
    • http://fontawesome.iohttp://fontawesome.io/license/In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/jolituzoji/71202027037.pdfIn PDF document text
    • https://s3.amazonaws.com/tomamujuf/present_continuous_exercises_worksheets.pdfIn PDF document text
    • https://s3.amazonaws.com/genijusemu/electrical_circuits_lecture_notes.pdfIn PDF document text
    • https://s3.amazonaws.com/bidivo/lurimaxepefev.pdfIn PDF document text
    • https://s3.amazonaws.com/tawosutosuxi/good_food_guide_voucher_list.pdfIn PDF document text
    • https://s3.amazonaws.com/datarofapakil/attack_on_titan_manga_wiki.pdfIn PDF document text
    • https://s3.amazonaws.com/tetofamuxulil/latoxodedamifekamukovigig.pdfIn PDF document text
    • https://s3.amazonaws.com/xesigeze/zirepokogugolufe.pdfIn PDF document text
    • https://s3.amazonaws.com/pazovugal/89921387440.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f913.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF913 1996 bytes
SHA-256: fe3dc828673b1d573b317f67a5953e0fa412431d28934c4dcb12acf085526eb5
font_01_sfnt_off0001028b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1028B 5196 bytes
SHA-256: 363bc402e7c8a1ef69451971eca84c8cb22f4033410c32a2bcddf3d59d6fef29
font_02_sfnt_off00011454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11454 11312 bytes
SHA-256: f595db6f255a4b586c486ffe643593a8a2847c1b07386ba98cca00128b6041b5