Malicious PDF — malware analysis report

Static analysis result for SHA-256 b50f855ddd1dced7…

MALICIOUS

PDF

126.8 KB Created: 2020-07-23 06:14:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-08-25
MD5: 3f44e397d66cba1ba774bfd8165208e0 SHA-1: 9fc7a33b637cfe54c5c50ec79a0ff797fa421cc0 SHA-256: b50f855ddd1dced7312a4ed80fc1aeedac98ff0f305c01d1c9576f5b01213f13
314 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains multiple heuristics indicating malicious intent, including a critical finding for a malicious redirector link and a link farm. The document body, though heavily obfuscated, contains text related to 'Ansible modules pdf' and 'wkhtmltopdf', suggesting a lure. The primary malicious IOC is the redirector URL, which likely leads to further stages of an attack. The ClamAV detection further supports the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • ClamAV: Pdf.Dropper.Agent-9108665-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-9108665-0
  • 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.
  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • 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.cc/pify?keyword=ansible+modules+pdf In PDF document text
    • http://files.bamboolearners.com/uploads/1/3/1/6/131606256/b9d05f0b185252.pdfIn PDF document text
    • http://files.beechstreetcenter.org/uploads/1/3/0/7/130739311/570884.pdfIn PDF document text
    • http://files.katianailedit.com/uploads/1/3/0/7/130775265/180496b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/7569/7830/files/dekebutumewi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0427/9900/5863/files/fesisejuwopuduwikokux.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/8581/5205/files/tidotizukevamikezoki.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/1437/4047/files/12537544165.pdfIn PDF document text
    • https://lipodixo.files.wordpress.com/2020/06/24019774272.pdfIn PDF document text
    • https://kajulak.files.wordpress.com/2020/07/magimepitabaso.pdfIn PDF document text
    • https://banakaximox.files.wordpress.com/2020/06/gezuketepazabasafolinifi.pdfIn PDF document text
    • https://roxigisap.files.wordpress.com/2020/07/nivokefoxabozesuruf.pdfIn PDF document text
    • https://babibased.files.wordpress.com/2020/07/79624036049.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0427/5198/3772/files/70374869602.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/6871/0309/files/nolagujabokejusoxa.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0436/9462/0837/files/dabupan.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/6006/0567/files/210599405.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0435/8438/9275/files/37813525432.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/26965864763.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/2205/6600/files/24599843263.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_off0001ac04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AC04 4812 bytes
SHA-256: 134c98d7b3f5b1983e5908fb3c297fc1189e46cf6c5ac58678d4e8f3df6f1fc0
font_01_sfnt_off0001bc36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BC36 15204 bytes
SHA-256: 9ebcb266fb112fbdc1573b26faea96b8104c7b2e42da2b4decb469015b323270