Malicious PDF — malware analysis report

Static analysis result for SHA-256 48f5f113fc3f628d…

MALICIOUS

PDF

127.2 KB Created: 2020-07-09 01:47:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-15
MD5: cdc7cf4ede2382e79f400e44d40f546c SHA-1: ff0e8dae4839b40c4a4c379113e3e4cbb7647597 SHA-256: 48f5f113fc3f628d82f24e192154953642c2e83f1c845c8ed50cb9e9363611bc
194 Risk Score

Malware Insights

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

The PDF contains a mass external link farm, with many links pointing to other PDFs. One prominent link redirects to malicious infrastructure via 'ttraff.cc'. The document body, though heavily obfuscated, contains text related to an 'English curriculum guide' and the redirector URL, suggesting a lure to trick users into downloading further malicious content. The ML classifier strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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.cc/wb?keyword=english%20curriculum%20guide%20may%202016%20pdf In PDF document text
    • http://files.hlhas.com/uploads/1/3/1/4/131483550/wuvoxipepuzan.pdfIn PDF document text
    • http://files.basscoastpost.com/uploads/1/3/0/7/130775025/5831108.pdfIn PDF document text
    • http://files.publichealthmuseum.org/uploads/1/3/1/3/131384789/a826b1b39.pdfIn PDF document text
    • http://files.thesolidrockshop.com/uploads/1/3/0/8/130813797/zaxisufibuxuxigusi.pdfIn PDF document text
    • http://files.sustainableetc.com/uploads/1/3/1/8/131856382/rudunijorewe-miluba-ratuw.pdfIn PDF document text
    • http://files.spottedvalleyappaloosa.com/uploads/1/3/0/7/130775846/dfcd85cc8b.pdfIn PDF document text
    • http://files.hallielee.com/uploads/1/3/2/8/132815961/5788720.pdfIn PDF document text
    • http://files.peterclarkmd.com/uploads/1/3/0/8/130814754/lubajifova-xerurularexepuv.pdfIn PDF document text
    • http://files.mylunarsign.com/uploads/1/3/1/8/131857482/6fcae3.pdfIn PDF document text
    • http://files.raleighmoravian.org/uploads/1/3/1/6/131637092/zavokebofakapez-labukoke-guvarasadojut.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://fijupuw.files.wordpress.com/2020/06/wowerewexukid.pdfIn PDF document text
    • https://wabufalij.files.wordpress.com/2020/06/58386599474.pdfIn PDF document text
    • https://sabunokig.files.wordpress.com/2020/06/daluv.pdfIn PDF document text
    • https://ruxurogizipo.files.wordpress.com/2020/07/34985222435.pdfIn PDF document text
    • https://fiwasaserop.files.wordpress.com/2020/06/seramuxuvirizada.pdfIn PDF document text
    • https://nurenin.files.wordpress.com/2020/07/susasofon.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/97697777452.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/mijafovaginidobu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/xibirinadinabamagumib.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/84005007378.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/mirizopenifipometetotagoz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/34707652888.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/85947343199.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_off0001ad73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AD73 5800 bytes
SHA-256: be942d2f22c45c2d20a90b7c9517943b7202d5a55d330093347bbc418633cfc4
font_01_sfnt_off0001c106.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C106 14704 bytes
SHA-256: 5a6797e0168cc7b862ea8ac5ce160d53d18f280e1db0b5fd3e77afb33cecd968