Malicious PDF — malware analysis report

Static analysis result for SHA-256 f99899bcb0fe70a3…

MALICIOUS

PDF

76.1 KB Created: 2021-02-26 09:04:58 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-03
MD5: 8169283ab4f03de5df892095812311c1 SHA-1: 3399edf0b9cbc07dee3fae1c806ff0e1ac39fbfe SHA-256: f99899bcb0fe70a3d87d69adf86784e17641e4565bbcfb5e2c810ba240f96700
252 Risk Score

Malware Insights

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

The PDF file contains a link farm designed to appear as a driver download, redirecting users to malicious infrastructure. The presence of a 'download button' heuristic and numerous external PDF links, including one pointing to a known malicious redirector, strongly suggests a phishing or malware distribution attempt. The ML classifier and ClamAV detection further corroborate the malicious nature of this document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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/award?keyword=hp+officejet+6500a+plus+driver+windows+10+64+bit In PDF document text
    • https://cdn-cms.f-static.net/uploads/4379231/normal_600b3d10bc984.pdfIn PDF document text
    • https://kuvijoxujav.weebly.com/uploads/1/3/4/2/134266993/33ca5de37745713.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4485930/normal_5ff02ba48aaae.pdfIn PDF document text
    • https://vedexojofidas.weebly.com/uploads/1/3/4/5/134581268/2058228.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389568/normal_5fe941139e9e9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385636/normal_6031e15c7dcb3.pdfIn PDF document text
    • http://sawemawe.mywebcommunity.org/how_to_put_baby_in_graco_snugride_35.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393751/normal_5fcf3bd6c9d8a.pdfIn PDF document text
    • https://xijexarara.weebly.com/uploads/1/3/4/0/134017378/7df713.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417643/normal_6030270449989.pdfIn PDF document text
    • http://vipadobotisituz.mygamesonline.org/commercial_electric_multimeter_mmm-8301s_manual.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/bokelur/degemit.pdfIn PDF document text
    • https://s3.amazonaws.com/tulosa/credit_collection_letter_template.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d67a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD67A 6036 bytes
SHA-256: fc3b80a7cc3ad1c48fbc674f387838ce017de2c661bce022821264b6fcdb98df
font_01_sfnt_off0000eb3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB3A 10136 bytes
SHA-256: 04eb6907f04039ea40973949653e8357717631cf5b67a2d6ba29c3006c8d8073
font_02_sfnt_off00010e37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E37 16144 bytes
SHA-256: 4b39140c652e6d058fe59e0172338ed7e0b8c56e7cdf0ba82c6c8c4172db5d18