Malicious PDF — malware analysis report

Static analysis result for SHA-256 3559ff3d7e534576…

MALICIOUS

PDF

44.5 KB Created: 2020-07-14 20:57:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-24
MD5: 7fa66a50bed79be0fc1eff01bdc5e85f SHA-1: df9fd492a732d150428fe9592aeb224cc4b10209 SHA-256: 3559ff3d7e534576337997e7d21b0ea5cfad305f963d22d1d546c59bd968a195
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF file contains a link to a redirector URL, which is a common tactic for distributing malware or leading users to phishing sites. The heuristic firings indicate that the PDF is acting as a link farm, directing users to numerous external PDF files, likely as part of a SEO poisoning or spam campaign. The primary malicious link identified is https://ttraff.ru/wb?keyword=make%20handwriting%20worksheets%20free%20online, which is designed to lure users under the guise of free worksheet creation.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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://ttraff.ru/wb?keyword=make%20handwriting%20worksheets%20free%20online In PDF document text
    • http://files.fcaky.com/uploads/1/3/1/4/131407698/5205caf.pdfIn PDF document text
    • http://files.mycorporatecounselor.com/uploads/1/3/1/4/131437983/1606706.pdfIn PDF document text
    • http://files.region6aha.com/uploads/1/3/1/4/131437834/joxerinumon.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://zuxejulo.files.wordpress.com/2020/07/tawimetodasawumumegel.pdfIn PDF document text
    • https://nexanofikade.files.wordpress.com/2020/07/27170279149.pdfIn PDF document text
    • https://magapabiv.files.wordpress.com/2020/06/92667861129.pdfIn PDF document text
    • https://lorujoxomejo.files.wordpress.com/2020/07/13340939588.pdfIn PDF document text
    • https://dajovofad.files.wordpress.com/2020/06/50312617570.pdfIn PDF document text
    • https://fojewel.files.wordpress.com/2020/06/5320902563.pdfIn PDF document text
    • https://semutodu.files.wordpress.com/2020/06/gujatopofoporuwetapazete.pdfIn PDF document text
    • https://jiledudosiso.files.wordpress.com/2020/07/savaxiximirunatilujulikoj.pdfIn PDF document text
    • https://zomifedig.files.wordpress.com/2020/06/86913876261.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/3049/4878/files/12258936568.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/7738/5892/files/kiguvi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/6630/2376/files/40179869085.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/19490865332.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0427/4490/5884/files/13282303681.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/1712/6563/files/beturewasagisazevamuvu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/6649/1042/files/likovijejuvupirezu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/1858/3192/files/jumaluzabatadodufivuwiwin.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/73875000904.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_off0000705b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x705B 5120 bytes
SHA-256: 9547573a8f24e440d6c097b5fc0f947de54e3f380a6ec4c5f7a35d2d580fb720
font_01_sfnt_off000081d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x81D0 10044 bytes
SHA-256: 14ec999d6850f89e725bbdc913eceb269c74f2b9cd6349dce8511f3eda9abc7e